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Aziz AB, Sugimoto JD, Hong SL, You YA, Bravo L, Roa C, Borja-Tabora C, Montellano MEB, Carlos J, de Los Reyes MRA, Alberto ER, Salvani-Bautista M, Kim HY, Njau I, Clemens R, Marks F, Tadesse BT. Indirect effectiveness of a novel SARS-COV-2 vaccine (SCB-2019) in unvaccinated household contacts in the Philippines: A cluster randomised analysis. J Infect 2024; 89:106260. [PMID: 39218309 DOI: 10.1016/j.jinf.2024.106260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 08/21/2024] [Accepted: 08/26/2024] [Indexed: 09/04/2024]
Abstract
BACKGROUND Though observational evidence supports indirect effects of SARS-CoV-2 vaccines, randomised experiments are lacking. To address this gap, the double-blinded, prospective follow-up of the household contacts (HHCs) of Philippine participants of the individually-randomised, placebo-controlled trial of the adjuvanted-subunit protein COVID-19 vaccine, SCB-2019, (EudraCT, 2020-004272-17; ClinicalTrials.gov, NCT04672395) was analyzed in a cluster-randomised fashion. METHODS Over an eight-week period, HHCs were followed by rRT-PCR and paired rapid antibody tests (RATs) to detect symptomatic (SCI, primary) and all (ACI, secondary) SARS-CoV-2 infection. A standard analysis estimated the indirect effectiveness of SCB-2019 for each endpoint, excluding HHC RAT-positive at enrollment. A secondary analysis employed enzyme-linked immunosorbent assay (ELISA) results to correct for suspected bias. FINDINGS SCB-2019 (N = 3470) and placebo (N = 3225) exposed HHCs contributed to at least one analysis. The standard analysis estimated that SCB-2019 reduced the risk of SCI by 83% (95% confidence/credible interval [CI: 32% to 96%), with no effect against ACI. The bias-corrected relative risk reduction was 97% (95% CI: 74% to 100%) for SCI and 79% (95% CI: 14% to 96%) for ACI, with an estimated one SARS-CoV-2 infection prevented per 4.8 households where one member received SCB-2019. INTERPRETATION SCB-2019 demonstrated bias-corrected indirect effectiveness against SARS-CoV-2 infection among HHC, even at a modest coverage level in the household (approximately 25%). Further research into the indirect effects of SARS-CoV-2 vaccines is needed to optimize the impact of limited doses in low and middle-income settings.
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Affiliation(s)
- Asma Binte Aziz
- International Vaccine Institute, Seoul 08826, Republic of Korea
| | - Jonathan Dewing Sugimoto
- International Vaccine Institute, Seoul 08826, Republic of Korea; Department of Epidemiology, University of Washington, 3980 15th Ave NE, Seattle, WA, USA; Vaccine and Infectious Disease Division, Fred Hutchinson Research Center, 1100 Fairview Avenue N., Seattle, WA, USA
| | - Sye Lim Hong
- International Vaccine Institute, Seoul 08826, Republic of Korea
| | - Young Ae You
- International Vaccine Institute, Seoul 08826, Republic of Korea
| | - Lulu Bravo
- University of the Philippines Manila, Ermita, Manila, Philippines
| | - Camilo Roa
- Manila Doctors Hospital, Manila, Philippines
| | | | | | | | | | | | | | - Hwa Young Kim
- International Vaccine Institute, Seoul 08826, Republic of Korea
| | - Irene Njau
- International Vaccine Institute, Seoul 08826, Republic of Korea
| | - Ralf Clemens
- International Vaccine Institute, Seoul 08826, Republic of Korea
| | - Florian Marks
- International Vaccine Institute, Seoul 08826, Republic of Korea; Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge CB2 0AW, United Kingdom; Heidelberg Institute of Global Health, University of Heidelberg, Im Neuenheimer Feld 130/3, 69120 Heidelberg, Germany; Madagascar Institute for Vaccine Research, University of Antananarivo, 3HM2+QH7, Antananarivo, Madagascar
| | - Birkneh Tilahun Tadesse
- International Vaccine Institute, Seoul 08826, Republic of Korea; Heidelberg Institute of Global Health, University of Heidelberg, Im Neuenheimer Feld 130/3, 69120 Heidelberg, Germany.
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2
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Tsang TK, Sullivan SG, Meng Y, Lai FTT, Fan M, Huang X, Lin Y, Peng L, Zhang C, Yang B, Ainslie KEC, Cowling BJ. Evaluating the impact of extended dosing intervals on mRNA COVID-19 vaccine effectiveness in adolescents. BMC Med 2024; 22:384. [PMID: 39267060 PMCID: PMC11396738 DOI: 10.1186/s12916-024-03597-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Accepted: 08/29/2024] [Indexed: 09/14/2024] Open
Abstract
BACKGROUND Extending the dosing interval of a primary series of mRNA COVID-19 vaccination has been employed to reduce myocarditis risk in adolescents, but previous evaluation of impact on vaccine effectiveness (VE) is limited to risk after second dose. METHODS We quantified the impact of the dosing interval based on case notifications and vaccination uptake in Hong Kong from January to April 2022, based on calendar-time proportional hazards models and matching approaches. RESULTS We estimated that the hazard ratio (HR) and odds ratio (OR) of infections after the second dose for extended (28 days or more) versus regular (21-27 days) dosing intervals ranged from 0.86 to 0.99 from calendar-time proportional hazards models, and from 0.85 to 0.87 from matching approaches, respectively. Adolescents in the extended dosing groups (including those who did not receive a second dose in the study period) had a higher hazard of infection than those with a regular dosing interval during the intra-dose period (HR 1.66; 95% CI 1.07, 2.59; p = 0.02) after the first dose. CONCLUSIONS Implementing an extended dosing interval should consider multiple factors including the degree of myocarditis risk, the degree of protection afforded by each dose, and the extra protection achievable using an extended dosing interval.
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Affiliation(s)
- Tim K Tsang
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing, Faculty of Medicine, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China.
- Laboratory of Data Discovery for Health Limited, Hong Kong Science and Technology Park, New Territories, Hong Kong Special Administrative Region, China.
| | - Sheena G Sullivan
- School of Clinical Sciences, Monash University, Melbourne, Australia
- Department of Epidemiology, University of California, Los Angeles, USA
| | - Yu Meng
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing, Faculty of Medicine, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China
| | - Francisco Tsz Tsun Lai
- Laboratory of Data Discovery for Health Limited, Hong Kong Science and Technology Park, New Territories, Hong Kong Special Administrative Region, China
- Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Min Fan
- Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Xiaotong Huang
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing, Faculty of Medicine, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China
| | - Yun Lin
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing, Faculty of Medicine, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China
| | - Liping Peng
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing, Faculty of Medicine, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China
| | - Chengyao Zhang
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing, Faculty of Medicine, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China
| | - Bingyi Yang
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing, Faculty of Medicine, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China
| | - Kylie E C Ainslie
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing, Faculty of Medicine, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China
- Centre for Infectious Disease Control, National Institute for Public Health and Environment (RIVM), Bilthoven, the Netherlands
| | - Benjamin J Cowling
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing, Faculty of Medicine, The University of Hong Kong, 7 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China.
- Laboratory of Data Discovery for Health Limited, Hong Kong Science and Technology Park, New Territories, Hong Kong Special Administrative Region, China.
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3
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Runge M, Karimian Z, Kheirandish M, Borghi G, Wodniak N, Fahmy K, Mantel C, Cherian T, Nabil Ahmed Said Z, Najafi F, Thneibat F, Ul-Haq Z, Fazid S, Ibrahim Salama I, Khosravi Shadmani F, Alrawashdeh A, Sirous S, Bellizzi S, Ahmed A, Lukwiya M, Rashidian A. COVID-19 Vaccine Effectiveness Studies against Symptomatic and Severe Outcomes during the Omicron Period in Four Countries in the Eastern Mediterranean Region. Vaccines (Basel) 2024; 12:906. [PMID: 39204033 PMCID: PMC11360574 DOI: 10.3390/vaccines12080906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Revised: 06/25/2024] [Accepted: 06/28/2024] [Indexed: 09/03/2024] Open
Abstract
Vaccine effectiveness (VE) studies provide real-world evidence to monitor vaccine performance and inform policy. The WHO Regional Office for the Eastern Mediterranean supported a regional study to assess the VE of COVID-19 vaccines against different clinical outcomes in four countries between June 2021 and August 2023. Health worker cohort studies were conducted in 2707 health workers in Egypt and Pakistan, of whom 171 experienced symptomatic laboratory-confirmed SARS-CoV-2 infection. Test-negative design case-control studies were conducted in Iran and Jordan in 4017 severe acute respiratory infection (SARI) patients (2347 controls and 1670 cases) during the Omicron variant dominant period. VE estimates were calculated for each study and pooled by study design for several vaccine types (BBIBP-CorV, AZD1222, BNT162b2, and mRNA-1273, among others). Among health workers, VE against symptomatic infection of a complete primary series could only be computed compared to partial vaccination, suggesting a benefit of providing an additional dose of mRNA vaccines (VE: 88.9%, 95%CI: 15.3-98.6%), while results were inconclusive for other vaccine products. Among SARI patients, VE against hospitalization of a complete primary series with any vaccine compared to non-vaccinated was 20.9% (95%CI: 4.5-34.5%). Effectiveness estimates for individual vaccines, booster doses, and secondary outcomes (intensive care unit admission and death) were inconclusive. Future VE studies will need to address challenges in both design and analysis when conducted late during a pandemic and will be able to utilize the strengthened capacities in countries.
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Affiliation(s)
| | - Zahra Karimian
- Division of Science, Information and Dissemination, WHO Regional Office for the Eastern Mediterranean, Cairo 11371, Egypt (M.K.)
- Heidelberg Institute of Global Health, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Mehrnaz Kheirandish
- Division of Science, Information and Dissemination, WHO Regional Office for the Eastern Mediterranean, Cairo 11371, Egypt (M.K.)
| | | | | | - Kamal Fahmy
- Division of Communicable Diseases, WHO Regional Office for the Eastern Mediterranean, Cairo 11516, Egypt
| | | | | | - Zeinab Nabil Ahmed Said
- Department of Medical Microbiology and Immunology, Faculty of Medicine (for Girls), Al-Azhar University, Cairo 11651, Egypt
| | - Farid Najafi
- Research Center for Environmental Determinants of Health (RCEDH), Health Institute, Kermanshah University of Medical Sciences, Kermanshah 6713954658, Iran (F.K.S.)
| | | | - Zia Ul-Haq
- Institute of Public Health and Social Sciences, Khyber Medical University, Peshawar 25100, Pakistan (S.F.)
- Institute of Health and Wellbeing, University of Glasgow, Glasgow G12 8QQ, UK
| | - Sheraz Fazid
- Institute of Public Health and Social Sciences, Khyber Medical University, Peshawar 25100, Pakistan (S.F.)
| | - Iman Ibrahim Salama
- Department of Community Medicine Research, National Research Centre, Cairo 12622, Egypt;
| | - Fatemeh Khosravi Shadmani
- Research Center for Environmental Determinants of Health (RCEDH), Health Institute, Kermanshah University of Medical Sciences, Kermanshah 6713954658, Iran (F.K.S.)
| | - Ahmad Alrawashdeh
- Department of Allied Medical Sciences, Jordan University of Science and Technology, Amman 3030, Jordan
| | | | | | - Amira Ahmed
- WHO Country Office for Egypt, Cairo 11516, Egypt
| | - Michael Lukwiya
- WHO Country Office for Pakistan, Islamabad P.O. Box 1013 44000, Pakistan
| | - Arash Rashidian
- Division of Science, Information and Dissemination, WHO Regional Office for the Eastern Mediterranean, Cairo 11371, Egypt (M.K.)
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4
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Sacco C, Manica M, Marziano V, Fabiani M, Mateo-Urdiales A, Guzzetta G, Merler S, Pezzotti P. The impact of underreported infections on vaccine effectiveness estimates derived from retrospective cohort studies. Int J Epidemiol 2024; 53:dyae077. [PMID: 38847783 PMCID: PMC11157963 DOI: 10.1093/ije/dyae077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 05/30/2024] [Indexed: 06/10/2024] Open
Abstract
BACKGROUND Surveillance data and vaccination registries are widely used to provide real-time vaccine effectiveness (VE) estimates, which can be biased due to underreported (i.e. under-ascertained and under-notified) infections. Here, we investigate how the magnitude and direction of this source of bias in retrospective cohort studies vary under different circumstances, including different levels of underreporting, heterogeneities in underreporting across vaccinated and unvaccinated, and different levels of pathogen circulation. METHODS We developed a stochastic individual-based model simulating the transmission dynamics of a respiratory virus and a large-scale vaccination campaign. Considering a baseline scenario with 22.5% yearly attack rate and 30% reporting ratio, we explored fourteen alternative scenarios, each modifying one or more baseline assumptions. Using synthetic individual-level surveillance data and vaccination registries produced by the model, we estimated the VE against documented infection taking as reference either unvaccinated or recently vaccinated individuals (within 14 days post-administration). Bias was quantified by comparing estimates to the known VE assumed in the model. RESULTS VE estimates were accurate when assuming homogeneous reporting ratios, even at low levels (10%), and moderate attack rates (<50%). A substantial downward bias in the estimation arose with homogeneous reporting and attack rates exceeding 50%. Mild heterogeneities in reporting ratios between vaccinated and unvaccinated strongly biased VE estimates, downward if cases in vaccinated were more likely to be reported and upward otherwise, particularly when taking as reference unvaccinated individuals. CONCLUSIONS In observational studies, high attack rates or differences in underreporting between vaccinated and unvaccinated may result in biased VE estimates. This study underscores the critical importance of monitoring data quality and understanding biases in observational studies, to more adequately inform public health decisions.
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Affiliation(s)
- Chiara Sacco
- ECDC Fellowship Programme, Field Epidemiology Path (EPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Mattia Manica
- Center for Health Emergencies, Fondazione Bruno Kessler, Trento, Italy
| | | | - Massimo Fabiani
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | | | - Giorgio Guzzetta
- Center for Health Emergencies, Fondazione Bruno Kessler, Trento, Italy
| | - Stefano Merler
- Center for Health Emergencies, Fondazione Bruno Kessler, Trento, Italy
| | - Patrizio Pezzotti
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
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5
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Rudolph AE, Khan FL, Shah A, Singh TG, Wiemken TL, Puzniak LA, Jodar L, McLaughlin JM. Effectiveness of BNT162b2 BA.4/5 Bivalent mRNA Vaccine Against Symptomatic COVID-19 Among Immunocompetent Individuals Testing at a Large US Retail Pharmacy. J Infect Dis 2024; 229:648-659. [PMID: 37925630 PMCID: PMC10938215 DOI: 10.1093/infdis/jiad474] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/05/2023] [Accepted: 10/27/2023] [Indexed: 11/05/2023] Open
Abstract
BACKGROUND Data on the effectiveness of BA.4/5 bivalent vaccine stratified by age and prior infection are lacking. METHODS This test-negative study used data from individuals ≥5 years of age testing for SARS-CoV-2 with symptoms (15 September 2022 to 31 January 2023) at a large national retail pharmacy chain. The exposure was receipt of 2-4 wild-type doses and a BNT162b2 BA.4/5 bivalent vaccine (>2 months since last wild-type dose). The outcome was a positive SARS-CoV-2 test. Absolute (vs unvaccinated) and relative (vs 2-4 wild-type doses) vaccine effectiveness (VE) were calculated as (1 - adjusted odds ratio from logistic regression) × 100. VE was stratified by age and self-reported prior infection. RESULTS Overall, 307 885 SARS-CoV-2 tests were included (7916 aged 5-11, 16 329 aged 12-17, and 283 640 aged ≥18 years). SARS-CoV-2 positivity was 39%; 21% were unvaccinated, 70% received 2-4 wild-type doses with no bivalent vaccine, and 9% received a BNT162b2 BA.4/5 bivalent dose. At a median of 1-2 months after BNT162b2 BA.4/5 bivalent vaccination, depending on age group, absolute VE was 22%-60% and was significantly higher among those reporting prior infection (range, 55%-79%) than not (range, no protection to 50%). Relative VE was 31%-64%. CONCLUSIONS BNT162b2 BA.4/5 bivalent showed early additional protection against Omicron-related symptomatic COVID-19, with hybrid immunity offering greater protection.
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Affiliation(s)
| | | | - Amy Shah
- Walgreens Center for Health and Wellbeing Research, Deerfield, Illinois, USA
| | - Tanya G Singh
- Walgreens Center for Health and Wellbeing Research, Deerfield, Illinois, USA
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6
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Li G, Gerlovin H, Figueroa Muñiz MJ, Wise JK, Madenci AL, Robins JM, Aslan M, Cho K, Gaziano JM, Lipsitch M, Casas JP, Hernán MA, Dickerman BA. Comparison of the Test-negative Design and Cohort Design With Explicit Target Trial Emulation for Evaluating COVID-19 Vaccine Effectiveness. Epidemiology 2024; 35:137-149. [PMID: 38109485 PMCID: PMC11022682 DOI: 10.1097/ede.0000000000001709] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
BACKGROUND Observational studies are used for estimating vaccine effectiveness under real-world conditions. The practical performance of two common approaches-cohort and test-negative designs-need to be compared for COVID-19 vaccines. METHODS We compared the cohort and test-negative designs to estimate the effectiveness of the BNT162b2 vaccine against COVID-19 outcomes using nationwide data from the United States Department of Veterans Affairs. Specifically, we (1) explicitly emulated a target trial using follow-up data and evaluated the potential for confounding using negative controls and benchmarking to a randomized trial, (2) performed case-control sampling of the cohort to confirm empirically that the same estimate is obtained, (3) further restricted the sampling to person-days with a test, and (4) implemented additional features of a test-negative design. We also compared their performance in limited datasets. RESULTS Estimated BNT162b2 vaccine effectiveness was similar under all four designs. Empirical results suggested limited residual confounding by healthcare-seeking behavior. Analyses in limited datasets showed evidence of residual confounding, with estimates biased downward in the cohort design and upward in the test-negative design. CONCLUSION Vaccine effectiveness estimates under a cohort design with explicit target trial emulation and a test-negative design were similar when using rich information from the VA healthcare system, but diverged in opposite directions when using a limited dataset. In settings like ours with sufficient information on confounders and other key variables, the cohort design with explicit target trial emulation may be preferable as a principled approach that allows estimation of absolute risks and facilitates interpretation of effect estimates.
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Affiliation(s)
- Guilin Li
- From the CAUSALab, Harvard T.H. Chan School of Public Health, Boston, MA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA
| | - Hanna Gerlovin
- Massachusetts Veterans Epidemiology Research and Information Center (MAVERIC), VA Boston Healthcare System, Boston, MA
| | - Michael J Figueroa Muñiz
- Massachusetts Veterans Epidemiology Research and Information Center (MAVERIC), VA Boston Healthcare System, Boston, MA
- Department of Biostatistics, Boston University School of Public Health, Boston, MA
| | - Jessica K Wise
- Massachusetts Veterans Epidemiology Research and Information Center (MAVERIC), VA Boston Healthcare System, Boston, MA
| | - Arin L Madenci
- From the CAUSALab, Harvard T.H. Chan School of Public Health, Boston, MA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA
- Department of Surgery, Boston Children's Hospital, Boston, MA
| | - James M Robins
- From the CAUSALab, Harvard T.H. Chan School of Public Health, Boston, MA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA
| | - Mihaela Aslan
- Cooperative Studies Program Clinical Epidemiology Research Center (CSP-CERC), VA Connecticut Healthcare System, West Haven, CT
- Department of Medicine, Yale University School of Medicine, New Haven, CT
| | - Kelly Cho
- Massachusetts Veterans Epidemiology Research and Information Center (MAVERIC), VA Boston Healthcare System, Boston, MA
- Division of Aging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - John Michael Gaziano
- Massachusetts Veterans Epidemiology Research and Information Center (MAVERIC), VA Boston Healthcare System, Boston, MA
- Division of Aging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Marc Lipsitch
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard TH Chan School of Public Health, Boston, MA
| | - Juan P Casas
- Massachusetts Veterans Epidemiology Research and Information Center (MAVERIC), VA Boston Healthcare System, Boston, MA
- Division of Aging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Miguel A Hernán
- From the CAUSALab, Harvard T.H. Chan School of Public Health, Boston, MA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA
| | - Barbra A Dickerman
- From the CAUSALab, Harvard T.H. Chan School of Public Health, Boston, MA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA
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7
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Wei J, Stoesser N, Matthews PC, Khera T, Gethings O, Diamond I, Studley R, Taylor N, Peto TEA, Walker AS, Pouwels KB, Eyre DW. Risk of SARS-CoV-2 reinfection during multiple Omicron variant waves in the UK general population. Nat Commun 2024; 15:1008. [PMID: 38307854 PMCID: PMC10837445 DOI: 10.1038/s41467-024-44973-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 01/10/2024] [Indexed: 02/04/2024] Open
Abstract
SARS-CoV-2 reinfections increased substantially after Omicron variants emerged. Large-scale community-based comparisons across multiple Omicron waves of reinfection characteristics, risk factors, and protection afforded by previous infection and vaccination, are limited. Here we studied ~45,000 reinfections from the UK's national COVID-19 Infection Survey and quantified the risk of reinfection in multiple waves, including those driven by BA.1, BA.2, BA.4/5, and BQ.1/CH.1.1/XBB.1.5 variants. Reinfections were associated with lower viral load and lower percentages of self-reporting symptoms compared with first infections. Across multiple Omicron waves, estimated protection against reinfection was significantly higher in those previously infected with more recent than earlier variants, even at the same time from previous infection. Estimated protection against Omicron reinfections decreased over time from the most recent infection if this was the previous or penultimate variant (generally within the preceding year). Those 14-180 days after receiving their most recent vaccination had a lower risk of reinfection than those >180 days from their most recent vaccination. Reinfection risk was independently higher in those aged 30-45 years, and with either low or high viral load in their most recent previous infection. Overall, the risk of Omicron reinfection is high, but with lower severity than first infections; both viral evolution and waning immunity are independently associated with reinfection.
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Affiliation(s)
- Jia Wei
- Nuffield Department of Medicine, University of Oxford, Oxford, UK.
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
| | - Nicole Stoesser
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Department of Infectious Diseases and Microbiology, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK
- The National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance at the University of Oxford, Oxford, UK
- The National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Philippa C Matthews
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
- The Francis Crick Institute, 1 Midland Road, London, UK
- Division of infection and immunity, University College London, London, UK
| | | | | | | | | | | | - Tim E A Peto
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Department of Infectious Diseases and Microbiology, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK
- The National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance at the University of Oxford, Oxford, UK
- The National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
| | - A Sarah Walker
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Oxford, UK
- The National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance at the University of Oxford, Oxford, UK
- MRC Clinical Trials Unit at UCL, UCL, London, UK
| | - Koen B Pouwels
- The National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance at the University of Oxford, Oxford, UK
- Health Economics Research Centre, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - David W Eyre
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Oxford, UK
- Department of Infectious Diseases and Microbiology, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK
- The National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance at the University of Oxford, Oxford, UK
- The National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
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8
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Chung H, Campitelli MA, Buchan SA, Campigotto A, Crowcroft NS, Gubbay JB, Jung JK, Karnauchow T, Katz K, McGeer AJ, McNally JD, Richardson DC, Richardson SE, Rosella LC, Russell ML, Schwartz KL, Simor A, Smieja M, Sundaram ME, Warshawsky BF, Zahariadis G, Kwong JC. Measuring waning protection from seasonal influenza vaccination during nine influenza seasons, Ontario, Canada, 2010/11 to 2018/19. Euro Surveill 2024; 29. [PMID: 38390652 PMCID: PMC10899815 DOI: 10.2807/1560-7917.es.2024.29.8.2300239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024] Open
Abstract
BackgroundWaning immunity from seasonal influenza vaccination can cause suboptimal protection during peak influenza activity. However, vaccine effectiveness studies assessing waning immunity using vaccinated and unvaccinated individuals are subject to biases.AimWe examined the association between time since vaccination and laboratory-confirmed influenza to assess the change in influenza vaccine protection over time.MethodsUsing linked laboratory and health administrative databases in Ontario, Canada, we identified community-dwelling individuals aged ≥ 6 months who received an influenza vaccine before being tested for influenza by RT-PCR during the 2010/11 to 2018/19 influenza seasons. We estimated the adjusted odds ratio (aOR) for laboratory-confirmed influenza by time since vaccination (categorised into intervals) and for every 28 days.ResultsThere were 53,065 individuals who were vaccinated before testing for influenza, with 10,264 (19%) influenza-positive cases. The odds of influenza increased from 1.05 (95% CI: 0.91-1.22) at 42-69 days after vaccination and peaked at 1.27 (95% CI: 1.04-1.55) at 126-153 days when compared with the reference interval (14-41 days). This corresponded to 1.09-times increased odds of influenza every 28 days (aOR = 1.09; 95% CI: 1.04-1.15). Individuals aged 18-64 years showed the greatest decline in protection against influenza A(H1N1) (aORper 28 days = 1.26; 95% CI: 0.97-1.64), whereas for individuals aged ≥ 65 years, it was against influenza A(H3N2) (aORper 28 days = 1.20; 95% CI: 1.08-1.33). We did not observe evidence of waning vaccine protection for individuals aged < 18 years.ConclusionsInfluenza vaccine protection wanes during an influenza season. Understanding the optimal timing of vaccination could ensure robust protection during seasonal influenza activity.
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Affiliation(s)
| | | | - Sarah A Buchan
- Public Health Ontario, Toronto, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
- ICES, Toronto, Canada
| | - Aaron Campigotto
- London Health Sciences Centre, London, Canada
- Hospital for Sick Children, Toronto, Canada
| | - Natasha S Crowcroft
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
- Centre for Vaccine Preventable Diseases, University of Toronto, Toronto, Canada
- Public Health Ontario, Toronto, Canada
- ICES, Toronto, Canada
| | - Jonathan B Gubbay
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
- Hospital for Sick Children, Toronto, Canada
- Public Health Ontario, Toronto, Canada
| | | | - Timothy Karnauchow
- Department of Pathology and Laboratory Medicine, University of Ottawa, Ottawa, Canada
- Children's Hospital of Eastern Ontario, Ottawa, Canada
| | - Kevin Katz
- North York General Hospital, Toronto, Canada
| | - Allison J McGeer
- Sinai Health System, Toronto, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
| | | | | | - Susan E Richardson
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
- Hospital for Sick Children, Toronto, Canada
| | - Laura C Rosella
- Public Health Ontario, Toronto, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
- ICES, Toronto, Canada
| | | | - Kevin L Schwartz
- Public Health Ontario, Toronto, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
- ICES, Toronto, Canada
| | - Andrew Simor
- Sunnybrook Health Sciences Centre, Toronto, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | | | - Maria E Sundaram
- Center for Clinical Epidemiology and Population Health, Marshfield Clinic Research Institute, Marshfield, United States
- Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
- ICES, Toronto, Canada
| | - Bryna F Warshawsky
- Western University, London, Canada
- Public Health Ontario, Toronto, Canada
| | - George Zahariadis
- Newfoundland and Labrador Public Health Laboratory, St. John's, Canada
- London Health Sciences Centre, London, Canada
| | - Jeffrey C Kwong
- ICES, Toronto, Canada
- Department of Family and Community Medicine, University of Toronto, Toronto, Canada
- University Health Network, Toronto, Canada
- Centre for Vaccine Preventable Diseases, University of Toronto, Toronto, Canada
- Public Health Ontario, Toronto, Canada
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9
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Kahn R, Feikin DR, Wiegand RE, Lipsitch M. EXAMINING BIAS FROM DIFFERENTIAL DEPLETION OF SUSCEPTIBLES IN VACCINE EFFECTIVENESS ESTIMATES IN SETTINGS OF WANING. Am J Epidemiol 2024; 193:232-234. [PMID: 37771045 PMCID: PMC10773472 DOI: 10.1093/aje/kwad191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 07/13/2023] [Accepted: 09/26/2023] [Indexed: 09/30/2023] Open
Affiliation(s)
- Rebecca Kahn
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, United States
- Center for Forecasting and Outbreak Analytics, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Daniel R Feikin
- Department of Immunizations, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | - Ryan E Wiegand
- National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Marc Lipsitch
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, United States
- Center for Forecasting and Outbreak Analytics, Centers for Disease Control and Prevention, Atlanta, GA, United States
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, United States
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10
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Hall VJ, Insalata F, Foulkes S, Kirwan P, Sparkes D, Atti A, Cole M, de Lacy E, Price L, Corrigan D, Brown CS, Islam J, Charlett A, Hopkins S. Effectiveness of BNT162b2 mRNA vaccine third doses and previous infection in protecting against SARS-CoV-2 infections during the Delta and Omicron variant waves; the UK SIREN cohort study September 2021 to February 2022. J Infect 2024; 88:30-40. [PMID: 37926119 DOI: 10.1016/j.jinf.2023.10.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 10/13/2023] [Accepted: 10/30/2023] [Indexed: 11/07/2023]
Abstract
Third doses of COVID-19 vaccines were widely deployed following the primary vaccine course waning and the emergence of the Omicron-variant. We investigated protection from third-dose vaccines and previous infection against SARS-CoV-2 infection during Delta-variant and Omicron-variant (BA.1 & BA.2) waves in our frequently PCR-tested cohort of healthcare-workers. Relative effectiveness of BNT162b2 third doses and infection-acquired immunity was assessed by comparing the time to PCR-confirmed infection in boosted participants with those with waned dose-2 protection (≥254 days after dose-2), by primary series vaccination type. Follow-up time was divided by dominant circulating variant: Delta 07 September 2021 to 30 November 2021, Omicron 13 December 2021t o 28 February 2022. We used a Cox regression model with adjustment/stratification for demographic characteristics and staff-type. We explored protection associated with vaccination, infection and both. We included 19,614 participants, 29% previously infected. There were 278 primary infections (4 per 10,000 person-days of follow-up) and 85 reinfections (0.8/10,000 person-days) during the Delta period and 2467 primary infections (43/10,000 person-days) and 881 reinfections (33/10,000) during the Omicron period. Relative Vaccine Effectiveness (VE) 0-2 months post-3rd dose (3rd dose) (3-doses BNT162b2) in the previously uninfected cohort against Delta infections was 63% (95% Confidence Interval (CI) 40%-77%) and was lower (35%) against Omicron infection (95% CI 21%-47%). The relative VE of 3rd dose (heterologous BNT162b2) was greater for primary course ChAdOX1 recipients, with VE 0-2 months post-3rd dose over ≥68% higher for both variants. Third-dose protection waned rapidly against Omicron, with no significant difference between two and three BNT162b2 doses observed after 4-months. Previous infection continued to provide additional protection against Omicron (67% (CI 56%-75%) 3-6 months post-infection), but this waned to about 25% after 9-months, approximately three times lower than against Delta. Infection rates surged with Omicron emergence. Third doses of BNT162b2 vaccine provided short-term protection, with rapid waning against Omicron infections. Protection associated with infections incurred before Omicron was markedly diminished against the Omicron wave. Our findings demonstrate the complexity of an evolving pandemic with the potential emergence of immune-escape variants and the importance of continued monitoring.
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Affiliation(s)
- Victoria J Hall
- UK Health Security Agency, 10 South Colonnade, London E14 4PU, United Kingdom.
| | - Ferdinando Insalata
- UK Health Security Agency, 10 South Colonnade, London E14 4PU, United Kingdom; Department of Mathematics, Imperial College London, London, SW7 2AZ, United Kingdom.
| | - Sarah Foulkes
- UK Health Security Agency, 10 South Colonnade, London E14 4PU, United Kingdom.
| | - Peter Kirwan
- UK Health Security Agency, 10 South Colonnade, London E14 4PU, United Kingdom; MRC Biostatistics Unit, University of Cambridge, Institute of Public Health, Forvie Site, Robinson Way, Cambridge CB2 0SR, United Kingdom.
| | - Dominic Sparkes
- UK Health Security Agency, 10 South Colonnade, London E14 4PU, United Kingdom.
| | - Ana Atti
- UK Health Security Agency, 10 South Colonnade, London E14 4PU, United Kingdom.
| | - Michelle Cole
- UK Health Security Agency, 10 South Colonnade, London E14 4PU, United Kingdom.
| | - Elen de Lacy
- Public Health Wales, 2 Capital Quarter, Tyndall Street, Cardiff CF10 4BZ, United Kingdom.
| | - Lesley Price
- Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, United Kingdom; Public Health Scotland, Gyle Square 1 South Gyle Crescent, Edinburgh EH12 9EB, United Kingdom.
| | - Diane Corrigan
- Public Health Agency Northern Ireland, Unit 12-22 Linenhall Street, Belfast BT2 8BS, United Kingdom.
| | - Colin S Brown
- UK Health Security Agency, 10 South Colonnade, London E14 4PU, United Kingdom.
| | - Jasmin Islam
- UK Health Security Agency, 10 South Colonnade, London E14 4PU, United Kingdom.
| | - Andre Charlett
- UK Health Security Agency, UK Health Security Agency, Nobel House, 17 Smith Square, London, SW1P 3JR.
| | - Susan Hopkins
- UK Health Security Agency, UK Health Security Agency, Nobel House, 17 Smith Square, London, SW1P 3JR.
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11
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Domnich A, Orsi A, Signori A, Chironna M, Manini I, Napoli C, Rizzo C, Panatto D, Icardi G. Waning intra-season vaccine effectiveness against influenza A(H3N2) underlines the need for more durable protection. Expert Rev Vaccines 2024; 23:380-388. [PMID: 38494919 DOI: 10.1080/14760584.2024.2331073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/12/2024] [Indexed: 03/19/2024]
Abstract
BACKGROUND The question of whether influenza vaccine effectiveness (VE) wanes over the winter season is still open and some contradictory findings have been reported. This study investigated the possible decline in protection provided by the available influenza vaccines. RESEARCH DESIGN AND METHODS An individual-level pooled analysis of six test-negative case-control studies conducted in Italy between the 2018/2019 and 2022/2023 seasons was performed. Multivariable logistic regression analyses were performed to estimate weekly change in the odds of testing positive for influenza 14 days after vaccination. RESULTS Of 6490 patients included, 1633 tested positive for influenza. Each week that had elapsed since vaccination was associated with an increase in the odds of testing positive for any influenza (4.9%; 95% CI: 2.0-8.0%) and for A(H3N2) (6.5%; 95% CI: 2.9-10.3%). This decline in VE was, however, significant only in children and older adults. A similar increase in the odds of testing positive was seen when the dataset was restricted to vaccinees only. Conversely, VE waning was less evident for A(H1N1)pdm09 or B strains. CONCLUSIONS Significant waning of VE, especially against influenza A(H3N2), may be one of the factors associated with suboptimal end-of-season VE. Next-generation vaccines should provide more durable protection against A(H3N2).
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Affiliation(s)
- Alexander Domnich
- Hygiene Unit, San Martino Policlinico Hospital - IRCCS for Oncology and Neurosciences, Genoa, Italy
| | - Andrea Orsi
- Hygiene Unit, San Martino Policlinico Hospital - IRCCS for Oncology and Neurosciences, Genoa, Italy
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
- Interuniversity Research Centre on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy
| | - Alessio Signori
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
| | - Maria Chironna
- Interdisciplinary Department of Medicine, University of Bari, Bari, Italy
| | - Ilaria Manini
- Interuniversity Research Centre on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | | | - Caterina Rizzo
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Donatella Panatto
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
- Interuniversity Research Centre on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy
| | - Giancarlo Icardi
- Hygiene Unit, San Martino Policlinico Hospital - IRCCS for Oncology and Neurosciences, Genoa, Italy
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
- Interuniversity Research Centre on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy
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12
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Tartof SY, Slezak JM, Puzniak L, Hong V, Frankland TB, Ackerson BK, Xie F, Takhar H, Ogun OA, Simmons S, Zamparo JM, Valluri SR, Jodar L, McLaughlin JM. Effectiveness of BNT162b2 BA.4/5 bivalent mRNA vaccine against a range of COVID-19 outcomes in a large health system in the USA: a test-negative case-control study. THE LANCET. RESPIRATORY MEDICINE 2023; 11:1089-1100. [PMID: 37898148 DOI: 10.1016/s2213-2600(23)00306-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/11/2023] [Accepted: 08/16/2023] [Indexed: 10/30/2023]
Abstract
BACKGROUND XBB-related omicron sublineages have recently replaced BA.4/5 as the predominant omicron sublineages in the USA and other regions globally. Despite preliminary signs of immune evasion of XBB sublineages, few data exist describing the real-world effectiveness of bivalent COVID-19 vaccines, especially against XBB-related illness. We aimed to investigate the effectiveness of the Pfizer--BioNTech BNT162b2 BA.4/5 bivalent vaccine against both BA.4/5-related and XBB-related disease in adults aged 18 years or older. METHODS In this test-negative case-control study, we estimated the effectiveness of the BNT162b2 BA.4/5 bivalent vaccine using data from electronic health records of Kaiser Permanente Southern California health system members aged 18 years or older who received at least two doses of the wild-type COVID-19 mRNA vaccines. Participants sought care for acute respiratory infection between Aug 31, 2022, and April 15, 2023, and were tested for SARS-CoV-2 via PCR tests. Relative vaccine effectiveness (≥2 doses of wild-type mRNA vaccine plus a BNT162b2 BA.4/5 bivalent booster vs ≥2 doses of a wild-type mRNA vaccine alone) and absolute vaccine effectiveness (vs unvaccinated individuals) was estimated against critical illness related to acute respiratory infection (intensive care unit [ICU] admission, mechanical ventilation, or inpatient death), hospital admission, emergency department or urgent care visits, and in-person outpatient encounters with odds ratios from logistic regression models adjusted for demographic and clinical factors. We stratified vaccine effectiveness estimates for hospital admission, emergency department or urgent care visits, and outpatient encounters by omicron sublineage (ie, likely BA.4/5-related vs likely XBB-related), time since bivalent booster receipt, age group, number of wild-type doses received, and immunocompromised status. This study is registered with ClinicalTrials.gov (NCT04848584). FINDINGS Analyses were conducted for 123 419 encounters (24 246 COVID-19 cases and 99 173 test-negative controls), including 4131 episode of critical illness (a subset of hospital admissions), 14 529 hospital admissions, 63 566 emergency department or urgent care visits, and 45 324 outpatient visits. 20 555 infections were BA.4/5 related and 3691 were XBB related. In adjusted analyses, relative vaccine effectiveness for those who received the BNT162b2 BA.4/5 bivalent booster compared with those who received at least two doses of a wild-type mRNA vaccine alone was an additional 50% (95% CI 23-68) against critical illness, an additional 39% (28-49) against hospital admission, an additional 35% (30-40) against emergency department or urgent care visits, and an additional 28% (22-33) against outpatient encounters. Waning of the bivalent booster from 0-3 months to 4-7 months after vaccination was evident for outpatient outcomes but was not detected for critical illness, hospital admission, and emergency department or urgent care outcomes. The relative effectiveness of the BNT162b2 BA.4/5 bivalent booster for XBB-related infections compared with BA.4/5-related infections was 56% (95% CI 12-78) versus 40% (27-50) for hospital admission; 34% (21-45) versus 36% (30-41) against emergency department or urgent care visits; and 29% (19-38) versus 27% (20-33) for outpatient encounters. INTERPRETATION By mid-April, 2023, individuals previously vaccinated only with wild-type vaccines had little protection against COVID-19-including hospital admission. A BNT162b2 BA.4/5 bivalent booster restored protection against a range of COVID-19 outcomes, including against XBB-related sublineages, with the most substantial protection observed against hospital admission and critical illness. FUNDING Pfizer.
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Affiliation(s)
- Sara Y Tartof
- Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA; Department of Health Systems Science, Kaiser Permanente Bernard J Tyson School of Medicine, Pasadena, CA USA.
| | - Jeff M Slezak
- Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA
| | | | - Vennis Hong
- Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA
| | - Timothy B Frankland
- Kaiser Permanente Hawaii Center for Integrated Health Care Research, Honolulu, HI, Hawaii
| | | | - Fagen Xie
- Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA
| | - Harpreet Takhar
- Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA
| | - Oluwaseye A Ogun
- Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA
| | - Sarah Simmons
- Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, CA, USA
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13
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Zachreson C, Tobin R, Szanyi J, Walker C, Cromer D, Shearer FM, Conway E, Ryan G, Cheng A, McCaw JM, Geard N. Individual variation in vaccine immune response can produce bimodal distributions of protection. Vaccine 2023; 41:6630-6636. [PMID: 37793975 DOI: 10.1016/j.vaccine.2023.09.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 09/14/2023] [Accepted: 09/14/2023] [Indexed: 10/06/2023]
Abstract
The ability for vaccines to protect against infectious diseases varies among individuals, but computational models employed to inform policy typically do not account for this variation. Here we examine this issue: we implement a model of vaccine efficacy developed in the context of SARS-CoV-2 in order to evaluate the general implications of modelling correlates of protection on the individual level. Due to high levels of variation in immune response, the distributions of individual-level protection emerging from this model tend to be highly dispersed, and are often bimodal. We describe the specification of the model, provide an intuitive parameterisation, and comment on its general robustness. We show that the model can be viewed as an intermediate between the typical approaches that consider the mode of vaccine action to be either "all-or-nothing" or "leaky". Our view based on this analysis is that individual variation in correlates of protection is an important consideration that may be crucial to designing and implementing models for estimating population-level impacts of vaccination programs.
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Affiliation(s)
- Cameron Zachreson
- School of Computing and Information Systems, The University of Melbourne, Parkville, Victoria, Australia.
| | - Ruarai Tobin
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Joshua Szanyi
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Camelia Walker
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria, Australia
| | - Deborah Cromer
- Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia
| | - Freya M Shearer
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Victoria, Australia; Telethon Kids Institute, Nedlands, Western Australia, Australia
| | - Eamon Conway
- The Walter and Eliza Hall Institute, Melbourne, Victoria, Australia
| | - Gerard Ryan
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Victoria, Australia; Telethon Kids Institute, Nedlands, Western Australia, Australia
| | - Allen Cheng
- Monash Infectious Diseases, Monash Health and School of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - James M McCaw
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Parkville, Victoria, Australia; School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria, Australia
| | - Nicholas Geard
- School of Computing and Information Systems, The University of Melbourne, Parkville, Victoria, Australia
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14
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Iwashyna TJ, Seelye S, Berkowitz TS, Pura J, Bohnert ASB, Bowling CB, Boyko EJ, Hynes DM, Ioannou GN, Maciejewski ML, O’Hare AM, Viglianti EM, Womer J, Prescott HC, Smith VA. Late Mortality After COVID-19 Infection Among US Veterans vs Risk-Matched Comparators: A 2-Year Cohort Analysis. JAMA Intern Med 2023; 183:1111-1119. [PMID: 37603339 PMCID: PMC10442778 DOI: 10.1001/jamainternmed.2023.3587] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 06/09/2023] [Indexed: 08/22/2023]
Abstract
Importance Despite growing evidence of persistent problems after acute COVID-19, how long the excess mortality risk associated with COVID-19 persists is unknown. Objective To measure the time course of differential mortality among Veterans who had a first-documented COVID-19 infection by separately assessing acute mortality from later mortality among matched groups with infected and uninfected individuals who survived and were uncensored at the start of each period. Design, Settings, and Participants This retrospective cohort study used prospectively collected health record data from Veterans Affairs hospitals across the US on Veterans who had COVID-19 between March 2020 and April 2021. Each individual was matched with up to 5 comparators who had not been infected with COVID-19 at the time of matching. This match balanced, on a month-by-month basis, the risk of developing COVID-19 using 37 variables measured in the 24 months before the date of the infection or match. A primary analysis censored comparators when they developed COVID-19 with inverse probability of censoring weighting in Cox regression. A secondary analysis did not censor. Data analyses were performed from April 2021 through June 2023. Exposure First-documented case of COVID-19 (SARS-CoV-2) infection. Main Outcome Measures Hazard ratios for all-cause mortality at clinically meaningful intervals after infection: 0 to 90, 91 to 180, 181 to 365, and 366 to 730 days. Results The study sample comprised 208 061 Veterans with first-documented COVID-19 infection (mean [SD] age, 60.5 (16.2) years; 21 936 (10.5) women; 47 645 [22.9] Black and 139 604 [67.1] White individuals) and 1 037 423 matched uninfected comparators with similar characteristics. Veterans with COVID-19 had an unadjusted mortality rate of 8.7% during the 2-year period after the initial infection compared with 4.1% among uninfected comparators, with censoring if the comparator later developed COVID-19-an adjusted hazard ratio (aHR) of 2.01 (95% CI, 1.98-2.04). The risk of excess death varied, being highest during days 0 to 90 after infection (aHR, 6.36; 95% CI, 6.20-6.51) and still elevated during days 91 to 180 (aHR, 1.18; 95% CI, 1.12-1.23). Those who survived COVID-19 had decreased mortality on days 181 to 365 (aHR, 0.92; 95% CI, 0.89-0.95) and 366 to 730 (aHR, 0.89; 95% CI, 0.85-0.92). These patterns were consistent across sensitivity analyses. Conclusion and Relevance The findings of this retrospective cohort study indicate that although overall 2-year mortality risk was worse among those infected with COVID-19, by day 180 after infection they had no excess mortality during the next 1.5 years.
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Affiliation(s)
- Theodore J. Iwashyna
- Veterans Affairs (VA) Center for Clinical Management Research, Ann Arbor VA, Ann Arbor, Michigan
- Department of Medicine, University of Michigan Medical School, Ann Arbor
- School of Medicine, Johns Hopkins University, Baltimore, Maryland
- School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - Sarah Seelye
- Veterans Affairs (VA) Center for Clinical Management Research, Ann Arbor VA, Ann Arbor, Michigan
| | - Theodore S. Berkowitz
- Center of Innovation to Accelerate Discovery and Practice Transformation, Durham VA Medical Center, Durham, North Carolina
| | - John Pura
- Center of Innovation to Accelerate Discovery and Practice Transformation, Durham VA Medical Center, Durham, North Carolina
| | - Amy S. B. Bohnert
- Veterans Affairs (VA) Center for Clinical Management Research, Ann Arbor VA, Ann Arbor, Michigan
- Departments of Anesthesiology and Psychiatry, University of Michigan Medical School, Ann Arbor
| | - C. Barrett Bowling
- Center of Innovation to Accelerate Discovery and Practice Transformation, Durham VA Medical Center, Durham, North Carolina
- Durham VA Geriatric Research Education and Clinical Center, Durham VA Medical Center, Durham, North Carolina
- Department of Medicine, Duke University, Durham, North Carolina
| | - Edward J. Boyko
- VA Puget Sound Health Care System Hospital and Specialty Medicine Service and Seattle-Denver Center of Innovation for Veteran Centered and Value Driven Care, Seattle, Washington
- Department of Medicine, University of Washington, Seattle
| | - Denise M. Hynes
- VA Center to Improve Veteran Involvement in Care, Portland, Oregon
- College of Public Health and Human Sciences and Center for Quantitative Life Sciences, Oregon State University, Corvallis
- School of Nursing, Oregon Health and Science University, Portland
| | - George N. Ioannou
- VA Puget Sound Health Care System Hospital and Specialty Medicine Service and Seattle-Denver Center of Innovation for Veteran Centered and Value Driven Care, Seattle, Washington
- Department of Medicine, University of Washington, Seattle
| | - Matthew L. Maciejewski
- Center of Innovation to Accelerate Discovery and Practice Transformation, Durham VA Medical Center, Durham, North Carolina
- Department of Medicine, Duke University, Durham, North Carolina
- Department of Population Health Sciences, Duke University, Durham, North Carolina
| | - Ann M. O’Hare
- VA Puget Sound Health Care System Hospital and Specialty Medicine Service and Seattle-Denver Center of Innovation for Veteran Centered and Value Driven Care, Seattle, Washington
- Department of Medicine, University of Washington, Seattle
| | - Elizabeth M. Viglianti
- Veterans Affairs (VA) Center for Clinical Management Research, Ann Arbor VA, Ann Arbor, Michigan
- Department of Medicine, University of Michigan Medical School, Ann Arbor
| | - James Womer
- School of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Hallie C. Prescott
- Veterans Affairs (VA) Center for Clinical Management Research, Ann Arbor VA, Ann Arbor, Michigan
- Department of Medicine, University of Michigan Medical School, Ann Arbor
| | - Valerie A. Smith
- Center of Innovation to Accelerate Discovery and Practice Transformation, Durham VA Medical Center, Durham, North Carolina
- Department of Medicine, Duke University, Durham, North Carolina
- Department of Population Health Sciences, Duke University, Durham, North Carolina
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Nikas A, Ahmed H, Zarnitsyna VI. Competing Heterogeneities in Vaccine Effectiveness Estimation. Vaccines (Basel) 2023; 11:1312. [PMID: 37631880 PMCID: PMC10458793 DOI: 10.3390/vaccines11081312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/27/2023] Open
Abstract
Understanding the waning of vaccine-induced protection is important for both immunology and public health. Population heterogeneities in underlying (pre-vaccination) susceptibility and vaccine response can cause measured vaccine effectiveness (mVE) to change over time, even in the absence of pathogen evolution and any actual waning of immune responses. We use multi-scale agent-based models parameterized using epidemiological and immunological data, to investigate the effect of these heterogeneities on mVE as measured by the hazard ratio. Based on our previous work, we consider the waning of antibodies according to a power law and link it to protection in two ways: (1) motivated by correlates of risk data and (2) using a within-host model of stochastic viral extinction. The effect of the heterogeneities is given by concise and understandable formulas, one of which is essentially a generalization of Fisher's fundamental theorem of natural selection to include higher derivatives. Heterogeneity in underlying susceptibility accelerates apparent waning, whereas heterogeneity in vaccine response slows down apparent waning. Our models suggest that heterogeneity in underlying susceptibility is likely to dominate. However, heterogeneity in vaccine response offsets <10% to >100% (median of 29%) of this effect in our simulations. Our study suggests heterogeneity is more likely to 'bias' mVE downwards towards the faster waning of immunity but a subtle bias in the opposite direction is also plausible.
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Affiliation(s)
- Ariel Nikas
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Hasan Ahmed
- Department of Biology, Emory University, Atlanta, GA 30322, USA;
| | - Veronika I. Zarnitsyna
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
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16
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Nikas A, Ahmed H, Zarnitsyna VI. Competing Heterogeneities in Vaccine Effectiveness Estimation. ARXIV 2023:arXiv:2305.01737v2. [PMID: 37205263 PMCID: PMC10187365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Understanding waning of vaccine-induced protection is important for both immunology and public health. Population heterogeneities in underlying (pre-vaccination) susceptibility and vaccine response can cause measured vaccine effectiveness (mVE) to change over time even in the absence of pathogen evolution and any actual waning of immune responses. We use a multi-scale agent-based models parameterized using epidemiological and immunological data, to investigate the effect of these heterogeneities on mVE as measured by the hazard ratio. Based on our previous work, we consider waning of antibodies according to a power law and link it to protection in two ways: 1) motivated by correlates of risk data and 2) using a within-host model of stochastic viral extinction. The effect of the heterogeneities is given by concise and understandable formulas, one of which is essentially a generalization of Fisher's fundamental theorem of natural selection to include higher derivatives. Heterogeneity in underlying susceptibility accelerates apparent waning, whereas heterogeneity in vaccine response slows down apparent waning. Our models suggest that heterogeneity in underlying susceptibility is likely to dominate. However, heterogeneity in vaccine response offsets <10% to >100% (median of 29%) of this effect in our simulations. Our methodology and results may be helpful in understanding competing heterogeneities and waning of immunity and vaccine-induced protection. Our study suggests heterogeneity is more likely to 'bias' mVE downwards towards faster waning of immunity but a subtle bias in the opposite direction is also plausible.
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Affiliation(s)
- Ariel Nikas
- Emory University School of Medicine, Department of Microbiology and Immunology, Atlanta, Georgia, United States of America
| | - Hasan Ahmed
- Emory University, Department of Biology, Atlanta, Georgia, United States of America
| | - Veronika I. Zarnitsyna
- Emory University School of Medicine, Department of Microbiology and Immunology, Atlanta, Georgia, United States of America
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Feikin DR, Higdon MM, Andrews N, Collie S, Deloria Knoll M, Kwong JC, Link-Gelles R, Pilishvili T, Patel MK. Assessing COVID-19 vaccine effectiveness against Omicron subvariants: Report from a meeting of the World Health Organization. Vaccine 2023; 41:2329-2338. [PMID: 36797097 PMCID: PMC9910025 DOI: 10.1016/j.vaccine.2023.02.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023]
Abstract
Emerging in November 2021, the SARS-CoV-2 Omicron variant of concern exhibited marked immune evasion resulting in reduced vaccine effectiveness against SARS-CoV-2 infection and symptomatic disease. Most vaccine effectiveness data on Omicron are derived from the first Omicron subvariant, BA.1, which caused large waves of infection in many parts of the world within a short period of time. BA.1, however, was replaced by BA.2 within months, and later by BA.4 and BA.5 (BA.4/5). These later Omicron subvariants exhibited additional mutations in the spike protein of the virus, leading to speculation that they might result in even lower vaccine effectiveness. To address this question, the World Health Organization hosted a virtual meeting on December 6, 2022, to review available evidence for vaccine effectiveness against the major Omicron subvariants up to that date. Data were presented from South Africa, the United Kingdom, the United States, and Canada, as well as the results of a review and meta-regression of studies that evaluated the duration of the vaccine effectiveness for multiple Omicron subvariants. Despite heterogeneity of results and wide confidence intervals in some studies, the majority of studies showed vaccine effectiveness tended to be lower against BA.2 and especially against BA.4/5, compared to BA.1, with perhaps faster waning against severe disease caused by BA.4/5 after a booster dose. The interpretation of these results was discussed and both immunological factors (i.e., more immune escape with BA.4/5) and methodological issues (e.g., biases related to differences in the timing of subvariant circulation) were possible explanations for the findings. COVID-19 vaccines still provide some protection against infection and symptomatic disease from all Omicron subvariants for at least several months, with greater and more durable protection against severe disease.
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Affiliation(s)
- Daniel R Feikin
- Department of Immunizations, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland.
| | - Melissa M Higdon
- International Vaccine Access Center, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Nick Andrews
- UK Health Security Agency, London, United Kingdom
| | | | - Maria Deloria Knoll
- International Vaccine Access Center, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - Ruth Link-Gelles
- National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, USA; U.S. Public Health Service Commissioned Corps, Rockville, MD, USA
| | - Tamara Pilishvili
- National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, USA
| | - Minal K Patel
- Department of Immunizations, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland; U.S. Public Health Service Commissioned Corps, Rockville, MD, USA
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18
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Lind ML, Robertson AJ, Silva J, Warner F, Coppi AC, Price N, Duckwall C, Sosensky P, Di Giuseppe EC, Borg R, Fofana MO, Ranzani OT, Dean NE, Andrews JR, Croda J, Iwasaki A, Cummings DAT, Ko AI, Hitchings MDT, Schulz WL. Association between primary or booster COVID-19 mRNA vaccination and Omicron lineage BA.1 SARS-CoV-2 infection in people with a prior SARS-CoV-2 infection: A test-negative case-control analysis. PLoS Med 2022; 19:e1004136. [PMID: 36454733 PMCID: PMC9714718 DOI: 10.1371/journal.pmed.1004136] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 10/26/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND The benefit of primary and booster vaccination in people who experienced a prior Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection remains unclear. The objective of this study was to estimate the effectiveness of primary (two-dose series) and booster (third dose) mRNA vaccination against Omicron (lineage BA.1) infection among people with a prior documented infection. METHODS AND FINDINGS We conducted a test-negative case-control study of reverse transcription PCRs (RT-PCRs) analyzed with the TaqPath (Thermo Fisher Scientific) assay and recorded in the Yale New Haven Health system from November 1, 2021, to April 30, 2022. Overall, 11,307 cases (positive TaqPath analyzed RT-PCRs with S-gene target failure [SGTF]) and 130,041 controls (negative TaqPath analyzed RT-PCRs) were included (median age: cases: 35 years, controls: 39 years). Among cases and controls, 5.9% and 8.1% had a documented prior infection (positive SARS-CoV-2 test record ≥90 days prior to the included test), respectively. We estimated the effectiveness of primary and booster vaccination relative to SGTF-defined Omicron (lineage BA.1) variant infection using a logistic regression adjusted for date of test, age, sex, race/ethnicity, insurance, comorbidities, social venerability index, municipality, and healthcare utilization. The effectiveness of primary vaccination 14 to 149 days after the second dose was 41.0% (95% confidence interval (CI): 14.1% to 59.4%, p 0.006) and 27.1% (95% CI: 18.7% to 34.6%, p < 0.001) for people with and without a documented prior infection, respectively. The effectiveness of booster vaccination (≥14 days after booster dose) was 47.1% (95% CI: 22.4% to 63.9%, p 0.001) and 54.1% (95% CI: 49.2% to 58.4%, p < 0.001) in people with and without a documented prior infection, respectively. To test whether booster vaccination reduced the risk of infection beyond that of the primary series, we compared the odds of infection among boosted (≥14 days after booster dose) and booster-eligible people (≥150 days after second dose). The odds ratio (OR) comparing boosted and booster-eligible people with a documented prior infection was 0.79 (95% CI: 0.54 to 1.16, p 0.222), whereas the OR comparing boosted and booster-eligible people without a documented prior infection was 0.54 (95% CI: 0.49 to 0.59, p < 0.001). This study's limitations include the risk of residual confounding, the use of data from a single system, and the reliance on TaqPath analyzed RT-PCR results. CONCLUSIONS In this study, we observed that primary vaccination provided significant but limited protection against Omicron (lineage BA.1) infection among people with and without a documented prior infection. While booster vaccination was associated with additional protection against Omicron BA.1 infection in people without a documented prior infection, it was not found to be associated with additional protection among people with a documented prior infection. These findings support primary vaccination in people regardless of documented prior infection status but suggest that infection history may impact the relative benefit of booster doses.
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Affiliation(s)
- Margaret L. Lind
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Alexander J. Robertson
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Julio Silva
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Frederick Warner
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, United States of America
- Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, Connecticut, United States of America
| | - Andreas C. Coppi
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, United States of America
- Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, Connecticut, United States of America
| | - Nathan Price
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, United States of America
- Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New Haven, Connecticut, United States of America
| | - Chelsea Duckwall
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Peri Sosensky
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Erendira C. Di Giuseppe
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Ryan Borg
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Mariam O. Fofana
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
| | - Otavio T. Ranzani
- Barcelona Institute for Global Health, ISGlobal, Universitat Pompeu Fabra (UPF), Barcelona, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
- Pulmonary Division, Heart Institute, Hospital das Clínicas, Faculdade de Medicina, São Paulo, Brazil
| | - Natalie E. Dean
- Department of Biostatistics & Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Jason R. Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, United States of America
| | - Julio Croda
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- Fiocruz Mato Grosso do Sul, Fundação Oswaldo Cruz, Campo Grande, Brazil
- Universidade Federal de Mato Grosso do Sul, Campo Grande, Brazil
| | - Akiko Iwasaki
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Derek A. T. Cummings
- Department of Biology, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Albert I. Ko
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States of America
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
| | - Matt D. T. Hitchings
- Department of Biostatistics, College of Public Health and Health Professions & College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Wade L. Schulz
- Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, United States of America
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
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19
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Bias in the association between advanced maternal age and stillbirth using left truncated data. Sci Rep 2022; 12:19214. [PMID: 36357770 PMCID: PMC9649623 DOI: 10.1038/s41598-022-23719-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 11/03/2022] [Indexed: 11/12/2022] Open
Abstract
Restriction to analysis of births that survive past a specified gestational age (typically 20 weeks gestation) leads to biased exposure-outcome associations. This bias occurs when the cause of restriction (early pregnancy loss) is influenced by both the exposure and unmeasured factors that also affect the outcome. The aim of this study is to estimate the magnitude of bias resulting from left truncated data in the association between advanced maternal age and stillbirth. We simulated data for the causal pathway under a collider-stratification mechanism. Simulation parameters were based on an observed birth cohort from Western Australia and a range of plausible values for the prevalence of early pregnancy loss, unmeasured factor U and the odds ratios for the selection effects. Selection effects included the effects of maternal age on early pregnancy loss, U on early pregnancy loss, and U on stillbirth. We compared the simulation scenarios to the observed birth cohort that was truncated to pregnancies that survived beyond 20 gestational weeks. We found evidence of marginal downward bias, which was most prominent for women aged 40 + years. Overall, we conclude that the magnitude of bias due to left truncation is minimal in the association between advanced maternal age and stillbirth.
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20
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Ranzani OT, Hitchings MDT, de Melo RL, de França GVA, Fernandes CDFR, Lind ML, Torres MSS, Tsuha DH, David LCS, Said RFC, Almiron M, de Oliveira RD, Cummings DAT, Dean NE, Andrews JR, Ko AI, Croda J. Effectiveness of an inactivated Covid-19 vaccine with homologous and heterologous boosters against Omicron in Brazil. Nat Commun 2022; 13:5536. [PMID: 36202800 PMCID: PMC9537178 DOI: 10.1038/s41467-022-33169-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 09/02/2022] [Indexed: 11/10/2022] Open
Abstract
The effectiveness of inactivated vaccines (VE) against symptomatic and severe COVID-19 caused by omicron is unknown. We conducted a nationwide, test-negative, case-control study to estimate VE for homologous and heterologous (BNT162b2) booster doses in adults who received two doses of CoronaVac in Brazil in the Omicron context. Analyzing 1,386,544 matched-pairs, VE against symptomatic disease was 8.6% (95% CI, 5.6-11.5) and 56.8% (95% CI, 56.3-57.3) in the period 8-59 days after receiving a homologous and heterologous booster, respectively. During the same interval, VE against severe Covid-19 was 73.6% (95% CI, 63.9-80.7) and 86.0% (95% CI, 84.5-87.4) after receiving a homologous and heterologous booster, respectively. Waning against severe Covid-19 after 120 days was only observed after a homologous booster. Heterologous booster might be preferable to individuals with completed primary series inactivated vaccine.
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Affiliation(s)
- Otavio T Ranzani
- Barcelona Institute for Global Health, ISGlobal, Universitat Pompeu Fabra (UPF), Barcelona, Spain
- Pulmonary Division, Heart Institute, Hospital das Clínicas, Faculdade de Medicina, São Paulo, SP, Brazil
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Matt D T Hitchings
- Department of Biostatistics, College of Public Health & Health Professions, University of Florida, Gainesville, FL, USA
| | - Rosana Leite de Melo
- Secretaria Extraordinária de Enfrentamento à Covid-19, Ministério da Saúde, Brasília, DF, Brazil
| | | | | | - Margaret L Lind
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | | | | | | | | | - Maria Almiron
- Pan American Health Organization, Brasilia, DF, Brazil
| | | | - Derek A T Cummings
- Department of Biology, University of Florida, Gainesville, FL, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Natalie E Dean
- Department of Biostatistics & Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
| | - Albert I Ko
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, BA, Brazil
| | - Julio Croda
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA.
- Fiocruz Mato Grosso do Sul, Fundação Oswaldo Cruz, Campo Grande, MS, Brazil.
- Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil.
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21
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Florentino PTV, Alves FJO, Cerqueira-Silva T, Oliveira VDA, Júnior JBS, Jantsch AG, Penna GO, Boaventura V, Werneck GL, Rodrigues LC, Pearce N, Barral-Netto M, Barreto ML, Paixão ES. Vaccine effectiveness of CoronaVac against COVID-19 among children in Brazil during the Omicron period. Nat Commun 2022; 13:4756. [PMID: 35963844 PMCID: PMC9375192 DOI: 10.1038/s41467-022-32524-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/03/2022] [Indexed: 01/07/2023] Open
Abstract
Although severe COVID-19 in children is rare, they may develop multisystem inflammatory syndrome, long-COVID and downstream effects of COVID-19, including social isolation and disruption of education. Data on the effectiveness of the CoronaVac vaccine is scarce during the Omicron period. In Brazil, children between 6 to 11 years are eligible to receive the CoronaVac vaccine. We conducted a test-negative design to estimate vaccine effectiveness using 197,958 tests from January 21, 2022, to April 15, 2022, during the Omicron dominant period in Brazil among children aged 6 to 11 years. The estimated vaccine effectiveness for symptomatic infection was 39.8% (95% CI 33.7-45.4) at ≥14 days post-second dose. For hospital admission vaccine effectiveness was 59.2% (95% CI 11.3-84.5) at ≥14 days. Two doses of CoronaVac in children during the Omicron period showed low levels of protection against symptomatic infection, and modest levels against severe illness.
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Affiliation(s)
- Pilar T V Florentino
- Centre of Data and Knowledge Integration for Health (CIDACS), Instituto Gonçalo Moniz Institute, Oswaldo Cruz Foundation (Fiocruz), Salvador, Brazil.
- Biomedical Science Institute, University of São Paulo, São Paulo, Brazil.
| | - Flávia J O Alves
- Centre of Data and Knowledge Integration for Health (CIDACS), Instituto Gonçalo Moniz Institute, Oswaldo Cruz Foundation (Fiocruz), Salvador, Brazil
| | - Thiago Cerqueira-Silva
- Gonçalo Moniz Institute, Oswaldo Cruz Foundation (Fiocruz), Salvador, Brazil
- Faculty of Medicine, Federal University of Bahia, Salvador, Brazil
| | - Vinicius de Araújo Oliveira
- Centre of Data and Knowledge Integration for Health (CIDACS), Instituto Gonçalo Moniz Institute, Oswaldo Cruz Foundation (Fiocruz), Salvador, Brazil
- Faculty of Medicine, Federal University of Bahia, Salvador, Brazil
| | - Juracy B S Júnior
- Public Health Institute, Federal University of Bahia, Salvador, Brazil
| | - Adelson G Jantsch
- Gonçalo Moniz Institute, Oswaldo Cruz Foundation (Fiocruz), Salvador, Brazil
| | - Gerson O Penna
- Tropical Medicine Centre, University of Brasília, Fiocruz School of Government, Brasília, Brazil
| | - Viviane Boaventura
- Gonçalo Moniz Institute, Oswaldo Cruz Foundation (Fiocruz), Salvador, Brazil
- Faculty of Medicine, Federal University of Bahia, Salvador, Brazil
| | - Guilherme L Werneck
- Department of Epidemiology, Social Medicine Institute, State University of Rio de Janeiro, Rio de Janeiro, Brazil
- Institute of Collective Health Studies, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Neil Pearce
- London School of Hygiene and Tropical Medicine, London, UK
| | - Manoel Barral-Netto
- Centre of Data and Knowledge Integration for Health (CIDACS), Instituto Gonçalo Moniz Institute, Oswaldo Cruz Foundation (Fiocruz), Salvador, Brazil
- Faculty of Medicine, Federal University of Bahia, Salvador, Brazil
| | - Mauricio L Barreto
- Centre of Data and Knowledge Integration for Health (CIDACS), Instituto Gonçalo Moniz Institute, Oswaldo Cruz Foundation (Fiocruz), Salvador, Brazil
| | - Enny S Paixão
- London School of Hygiene and Tropical Medicine, London, UK
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22
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Lee D, Counard C, Tang A, Brister S, Ezike N. Notes from the Field: COVID-19-Associated Mortality Risk Among Long-Term Care Facility Residents and Community-Dwelling Adults Aged ≥65 Years - Illinois, December 2020 and January 2022. MMWR. MORBIDITY AND MORTALITY WEEKLY REPORT 2022; 71:803-805. [PMID: 35709016 DOI: 10.15585/mmwr.mm7124a4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
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23
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Hitchings MDT, Ranzani OT, Lind ML, Dorion M, D'Agostini TL, de Paula RC, de Paula OFP, de Moura Villela EF, Scaramuzzini Torres MS, de Oliveira SB, Schulz W, Almiron M, Said R, de Oliveira RD, Vieira da Silva P, de Araújo WN, Gorinchteyn JC, Dean NE, Andrews JR, Cummings DAT, Ko AI, Croda J. Change in covid-19 risk over time following vaccination with CoronaVac: test negative case-control study. BMJ 2022; 377:e070102. [PMID: 35697361 PMCID: PMC9189440 DOI: 10.1136/bmj-2022-070102] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE To estimate the change in odds of covid-19 over time following primary series completion of the inactivated whole virus vaccine CoronaVac (Sinovac Biotech) in São Paulo State, Brazil. DESIGN Test negative case-control study. SETTING Community testing for covid-19 in São Paulo State, Brazil. PARTICIPANTS Adults aged ≥18 years who were residents of São Paulo state, had received two doses of CoronaVac, did not have a laboratory confirmed SARS-CoV-2 infection before vaccination, and underwent reverse transcription polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 from 17 January to 14 December 2021. Cases were matched to test negative controls by age (in 5 year bands), municipality of residence, healthcare worker status, and epidemiological week of RT-PCR test. MAIN OUTCOME MEASURES RT-PCR confirmed symptomatic covid-19 and associated hospital admissions and deaths. Conditional logistic regression was adjusted for sex, number of covid-19 associated comorbidities, race, and previous acute respiratory illness. RESULTS From 202 741 eligible people, 52 170 cases with symptomatic covid-19 and 69 115 test negative controls with covid-19 symptoms were formed into 43 257 matched sets. Adjusted odds ratios of symptomatic covid-19 increased with time since completion of the vaccination series. The increase in odds was greater in younger people and among healthcare workers, although sensitivity analyses suggested that this was in part due to bias. In addition, the adjusted odds ratios of covid-19 related hospital admission or death significantly increased with time compared with the odds 14-41 days after series completion: from 1.25 (95% confidence interval 1.04 to 1.51) at 70-97 days up to 1.94 (1.41 to 2.67) from 182 days onwards. CONCLUSIONS Significant increases in the risk of moderate and severe covid-19 outcomes occurred three months after primary vaccination with CoronaVac among people aged 65 and older. These findings provide supportive evidence for the implementation of vaccine boosters in these populations who received this inactivated vaccine. Studies of waning should include analyses designed to uncover common biases.
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Affiliation(s)
- Matt D T Hitchings
- Department of Biostatistics, College of Public Health and Health Professions, University of Florida, Gainesville, FL, USA
| | - Otavio T Ranzani
- Barcelona Institute for Global Health, ISGlobal, Barcelona, Spain
- Pulmonary Division, Heart Institute (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Margaret L Lind
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Murilo Dorion
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | | | | | | | | | | | | | - Wade Schulz
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Maria Almiron
- Pan American Health Organization, Brasília, DF, Brazil
| | - Rodrigo Said
- Pan American Health Organization, Brasília, DF, Brazil
| | | | | | - Wildo Navegantes de Araújo
- Pan American Health Organization, Brasília, DF, Brazil
- Universidade de Brasília, Brasília, DF, Brazil
- National Institute for Science and Technology for Health Technology Assessment, Porto Alegre, RS, Brazil
| | | | - Natalie E Dean
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
- Contributed equally
| | - Derek A T Cummings
- Department of Biology, University of Florida, Gainesville, FL, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
- Contributed equally
| | - Albert I Ko
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, BA, Brazil
- Contributed equally
| | - Julio Croda
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
- Universidade Federal de Mato Grosso do Sul - UFMS, Campo Grande, MS, Brazil
- Fiocruz Mato Grosso do Sul, Fundação Oswaldo Cruz, Campo Grande, MS, Brazil
- Contributed equally
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Kahn R, Schrag SJ, Verani JR, Lipsitch M. Identifying and Alleviating Bias Due to Differential Depletion of Susceptible People in Postmarketing Evaluations of COVID-19 Vaccines. Am J Epidemiol 2022; 191:800-811. [PMID: 35081612 PMCID: PMC8807238 DOI: 10.1093/aje/kwac015] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 01/09/2022] [Accepted: 01/24/2022] [Indexed: 01/06/2023] Open
Abstract
Recent studies have provided key information about SARS-CoV-2 vaccines' efficacy and effectiveness (VE). One important question that remains is whether the protection conferred by vaccines wanes over time. However, estimates over time are subject to bias from differential depletion of susceptible individuals between vaccinated and unvaccinated groups. We examined the extent to which biases occur under different scenarios and assessed whether serological testing has the potential to correct this bias. By identifying nonvaccine antibodies, these tests could identify individuals with prior infection. We found that in scenarios with high baseline VE, differential depletion of susceptible individuals created minimal bias in VE estimates, suggesting that any observed declines are likely not due to spurious waning alone. However, if baseline VE was lower, the bias for leaky vaccines (which reduce individual probability of infection given contact) was larger and should be corrected for by excluding individuals with past infection if the mechanism is known to be leaky. Conducting analyses both unadjusted and adjusted for past infection could give lower and upper bounds for the true VE. Studies of VE should therefore enroll individuals regardless of prior infection history but also collect information, ideally through serological testing, on this critical variable.
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Affiliation(s)
- Rebecca Kahn
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States
- COVID-19 Response, US Centers for Disease Control and Prevention, Atlanta, Georgia, United States
| | - Stephanie J Schrag
- COVID-19 Response, US Centers for Disease Control and Prevention, Atlanta, Georgia, United States
| | - Jennifer R Verani
- COVID-19 Response, US Centers for Disease Control and Prevention, Atlanta, Georgia, United States
| | - Marc Lipsitch
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States
- COVID-19 Response, US Centers for Disease Control and Prevention, Atlanta, Georgia, United States
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States
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25
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Fay MP, Hunsberger S, Follmann D. Risk Heterogeneity and the Illusion of Waning Vaccine Efficacy. Ann Intern Med 2022; 175:444-445. [PMID: 34928696 DOI: 10.7326/m21-3609] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Michael P Fay
- National Institute of Allergy and Infectious Diseases, Bethesda, Maryland (M.P.F., S.H., D.F.)
| | - Sally Hunsberger
- National Institute of Allergy and Infectious Diseases, Bethesda, Maryland (M.P.F., S.H., D.F.)
| | - Dean Follmann
- National Institute of Allergy and Infectious Diseases, Bethesda, Maryland (M.P.F., S.H., D.F.)
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26
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Ioannou GN, Locke ER, Green PK, Berry K. Comparison of Moderna versus Pfizer-BioNTech COVID-19 vaccine outcomes: A target trial emulation study in the U.S. Veterans Affairs healthcare system. EClinicalMedicine 2022; 45:101326. [PMID: 35261970 PMCID: PMC8896984 DOI: 10.1016/j.eclinm.2022.101326] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 01/27/2022] [Accepted: 02/10/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND mRNA COVID-19 vaccines manufactured by Pfizer-BioNTech (BNT162b2) and Moderna (mRNA-1273) have been shown to be efficacious but have not been compared in head-to-head clinical trials. METHODS We designed this observational study to emulate a target trial of COVID-19 vaccination by BNT162b2 versus mRNA-1273 among persons who underwent vaccination in the national U.S. Veterans Affairs (VA) healthcare system from 11/12/2020 to 25/03/2021 using combined VA and Medicare electronic health records. We identified the best matching mRNA-1273 recipient(s) for each BNT162b2 recipient, using exact/coarsened-exact matching (calendar week, VA integrated service network, age buckets and Charlson comorbidity index buckets) followed by propensity score matching. Vaccine recipients were followed from the date of first vaccine dose until 25/08/2021 for the development of SARS-CoV-2 infection, SARS-CoV-2-related hospitalization or SARS-CoV-2-related death. FINDINGS Each group included 902,235 well-matched vaccine recipients, followed for a mean of 192 days, during which 16,890 SARS-CoV-2 infections, 3591 SARS-CoV-2-related hospitalizations and 381 SARS-CoV-2-related deaths were documented. Compared to BNT162b2, mRNA-1273 recipients had significantly lower risk of SARS-CoV-2 infection (adjusted hazard ratio [aHR] 0.736, 95% CI 0.696-0.779) and SARS-CoV-2-related hospitalization (aHR 0.633, 95% CI 0.562-0.713), which persisted across all age groups, comorbidity burden categories and black/white race. The differences between mRNA-1273 and BNT162b2 in risk of infection or hospitalization were progressively greater when the follow-up period was longer, i.e. extending to March 31, June 30 or August 25, 2021. These differences were more pronounced when we analyzed separately the outcomes that occurred during the follow-up period from July 1 to August 25, 2021 when the Delta variant became predominant in the U.S. (aHR for infection 0.584, 95% CI 0.533-0.639 and aHR for hospitalization 0.387, 95% 0.311-0.482). SARS-CoV-2-related deaths were less common in mRNA-1273 versus BNT162b2 recipients (168 versus 213) but this difference was not statistically significant (aHR 0.808, 95% CI 0.592-1.103). INTERPRETATION In conclusion, although absolute rates of infection, hospitalization and death in both vaccine groups were low regardless of the vaccine received, our data suggests that compared to BNT162b2, vaccination with mRNA-1273 resulted in significantly lower rates of SARS-CoV-2-infection and SARS-CoV-2-related hospitalization. These differences were greater with longer follow-up time since vaccination and even more pronounced in the Delta variant era. FUNDING U.S. Department of Veterans Affairs, grant numbers COVID19-8900-11 and C19 21-278.
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Affiliation(s)
- George N. Ioannou
- Division of Gastroenterology, Veterans Affairs Puget Sound Healthcare System and University of Washington, 1660 S. Columbian Way, Seattle, WA 98108, USA
- Research and Development, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
- Corresponding author at: Division of Gastroenterology, Veterans Affairs Puget Sound Healthcare System and University of Washington, 1660 S. Columbian Way, Seattle, WA 98108, USA.
| | - Emily R. Locke
- Research and Development, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
| | - Pamela K. Green
- Research and Development, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
| | - Kristin Berry
- Research and Development, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
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Abrignani MG, Murrone A, De Luca L, Roncon L, Di Lenarda A, Valente S, Caldarola P, Riccio C, Oliva F, Gulizia MM, Gabrielli D, Colivicchi F. COVID-19, Vaccines, and Thrombotic Events: A Narrative Review. J Clin Med 2022; 11:948. [PMID: 35207220 PMCID: PMC8880092 DOI: 10.3390/jcm11040948] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/08/2022] [Accepted: 02/09/2022] [Indexed: 02/05/2023] Open
Abstract
The coronavirus disease 2019 (COVID-19), a deadly pandemic that has affected millions of people worldwide, is associated with cardiovascular complications, including venous and arterial thromboembolic events. Viral spike proteins, in fact, may promote the release of prothrombotic and inflammatory mediators. Vaccines, coding for the spike protein, are the primary means for preventing COVID-19. However, some unexpected thrombotic events at unusual sites, most frequently located in the cerebral venous sinus but also splanchnic, with associated thrombocytopenia, have emerged in subjects who received adenovirus-based vaccines, especially in fertile women. This clinical entity was soon recognized as a new syndrome, named vaccine-induced immune thrombotic thrombocytopenia, probably caused by cross-reacting anti-platelet factor-4 antibodies activating platelets. For this reason, the regulatory agencies of various countries restricted the use of adenovirus-based vaccines to some age groups. The prevailing opinion of most experts, however, is that the risk of developing COVID-19, including thrombotic complications, clearly outweighs this potential risk. This point-of-view aims at providing a narrative review of epidemiological issues, clinical data, and pathogenetic hypotheses of thrombosis linked to both COVID-19 and its vaccines, helping medical practitioners to offer up-to-date and evidence-based counseling to their often-alarmed patients with acute or chronic cardiovascular thrombotic events.
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Affiliation(s)
| | - Adriano Murrone
- Cardiology-UTIC, Hospitals of Città di Castello and Gubbio-Gualdo Tadino, AUSL Umbria 1, 06100 Perugia, Italy;
| | - Leonardo De Luca
- Cardiology, Cardio-Thoraco-Vascular Department, San Camillo Forlanini Hospital, 00100 Rome, Italy; (L.D.L.); (D.G.)
| | - Loris Roncon
- Cardiology Department, Santa Maria della Misericordia Hospital, 45100 Rovigo, Italy;
| | - Andrea Di Lenarda
- Cardiovascular and Sports Medicine Department, Azienda Sanitaria Universitaria Giuliano Isontina-ASUGI, 34100 Trieste, Italy;
| | - Serafina Valente
- Clinical Surgical Cardiology (UTIC), A.O.U. Senese, Santa Maria alle Scotte Hospital, 53100 Siena, Italy;
| | | | - Carmine Riccio
- Follow-Up of the Post-Acute Patient Unit, Cardio-Vascular Department, A.O.R.N. Sant’Anna and San Sebastiano, 81000 Caserta, Italy;
| | - Fabrizio Oliva
- Cardiology 1-Hemodynamics, Cardiological Intensive Care Unit, Cardiothoracovascular Department “A. De Gasperis”, ASST Grande Ospedale Metropolitano Niguarda, 20100 Milan, Italy;
| | - Michele M. Gulizia
- Cardiology Department, Garibaldi-Nesima Hospital, Company of National Importance and High Specialization “Garibaldi”, 95100 Catania, Italy;
- Heart Care Foundation, 50121 Florence, Italy
| | - Domenico Gabrielli
- Cardiology, Cardio-Thoraco-Vascular Department, San Camillo Forlanini Hospital, 00100 Rome, Italy; (L.D.L.); (D.G.)
| | - Furio Colivicchi
- Clinical and Rehabilitation Cardiology Department, Presidio Ospedaliero San Filippo Neri—ASL Roma 1, 00100 Rome, Italy;
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Katikireddi SV, Cerqueira-Silva T, Vasileiou E, Robertson C, Amele S, Pan J, Taylor B, Boaventura V, Werneck GL, Flores-Ortiz R, Agrawal U, Docherty AB, McCowan C, McMenamin J, Moore E, Ritchie LD, Rudan I, Shah SA, Shi T, Simpson CR, Barreto ML, Oliveira VDA, Barral-Netto M, Sheikh A. Two-dose ChAdOx1 nCoV-19 vaccine protection against COVID-19 hospital admissions and deaths over time: a retrospective, population-based cohort study in Scotland and Brazil. Lancet 2022; 399:25-35. [PMID: 34942103 PMCID: PMC8687670 DOI: 10.1016/s0140-6736(21)02754-9] [Citation(s) in RCA: 87] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/08/2021] [Accepted: 11/25/2021] [Indexed: 01/19/2023]
Abstract
BACKGROUND Reports suggest that COVID-19 vaccine effectiveness is decreasing, but whether this reflects waning or new SARS-CoV-2 variants-especially delta (B.1.617.2)-is unclear. We investigated the association between time since two doses of ChAdOx1 nCoV-19 vaccine and risk of severe COVID-19 outcomes in Scotland (where delta was dominant), with comparative analyses in Brazil (where delta was uncommon). METHODS In this retrospective, population-based cohort study in Brazil and Scotland, we linked national databases from the EAVE II study in Scotland; and the COVID-19 Vaccination Campaign, Acute Respiratory Infection Suspected Cases, and Severe Acute Respiratory Infection/Illness datasets in Brazil) for vaccination, laboratory testing, clinical, and mortality data. We defined cohorts of adults (aged ≥18 years) who received two doses of ChAdOx1 nCoV-19 and compared rates of severe COVID-19 outcomes (ie, COVID-19 hospital admission or death) across fortnightly periods, relative to 2-3 weeks after the second dose. Entry to the Scotland cohort started from May 19, 2021, and entry to the Brazil cohort started from Jan 18, 2021. Follow-up in both cohorts was until Oct 25, 2021. Poisson regression was used to estimate rate ratios (RRs) and vaccine effectiveness, with 95% CIs. FINDINGS 1 972 454 adults received two doses of ChAdOx1 nCoV-19 in Scotland and 42 558 839 in Brazil, with longer follow-up in Scotland because two-dose vaccination began earlier in Scotland than in Brazil. In Scotland, RRs for severe COVID-19 increased to 2·01 (95% CI 1·54-2·62) at 10-11 weeks, 3·01 (2·26-3·99) at 14-15 weeks, and 5·43 (4·00-7·38) at 18-19 weeks after the second dose. The pattern of results was similar in Brazil, with RRs of 2·29 (2·01-2·61) at 10-11 weeks, 3·10 (2·63-3·64) at 14-15 weeks, and 4·71 (3·83-5·78) at 18-19 weeks after the second dose. In Scotland, vaccine effectiveness decreased from 83·7% (95% CI 79·7-87·0) at 2-3 weeks, to 75·9% (72·9-78·6) at 14-15 weeks, and 63·7% (59·6-67·4) at 18-19 weeks after the second dose. In Brazil, vaccine effectiveness decreased from 86·4% (85·4-87·3) at 2-3 weeks, to 59·7% (54·6-64·2) at 14-15 weeks, and 42·2% (32·4-50·6) at 18-19 weeks. INTERPRETATION We found waning vaccine protection of ChAdOx1 nCoV-19 against COVID-19 hospital admissions and deaths in both Scotland and Brazil, this becoming evident within three months of the second vaccine dose. Consideration needs to be given to providing booster vaccine doses for people who have received ChAdOx1 nCoV-19. FUNDING UK Research and Innovation (Medical Research Council), Scottish Government, Research and Innovation Industrial Strategy Challenge Fund, Health Data Research UK, Fiocruz, Fazer o Bem Faz Bem Programme; Conselho Nacional de Desenvolvimento Científico e Tecnológico, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro. TRANSLATION For the Portuguese translation of the abstract see Supplementary Materials section.
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Affiliation(s)
- Srinivasa Vittal Katikireddi
- MRC/CSO Social and Public Health Sciences Unit, University of Glasgow, Glasgow, UK; Public Health Scotland, Glasgow, UK
| | - Thiago Cerqueira-Silva
- Instituto Gonçalo Moniz, Fiocruz, Bahia, Brazil; Universidade Federal de Bahia, Salvador, Bahia, Brazil
| | | | - Chris Robertson
- Public Health Scotland, Glasgow, UK; Department of Mathematics and Statistics, University of Strathclyde, Glasgow, UK
| | - Sarah Amele
- MRC/CSO Social and Public Health Sciences Unit, University of Glasgow, Glasgow, UK
| | - Jiafeng Pan
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, UK
| | | | - Viviane Boaventura
- Instituto Gonçalo Moniz, Fiocruz, Bahia, Brazil; Universidade Federal de Bahia, Salvador, Bahia, Brazil
| | - Guilherme Loureiro Werneck
- Departamento de Epidemiologia of Instituto de Medicina Social, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Utkarsh Agrawal
- School of Medicine, University of St Andrews, St Andrews, UK
| | | | - Colin McCowan
- School of Medicine, University of St Andrews, St Andrews, UK
| | | | | | | | - Igor Rudan
- Usher Institute, University of Edinburgh, Edinburgh, UK
| | | | - Ting Shi
- Usher Institute, University of Edinburgh, Edinburgh, UK
| | - Colin R Simpson
- Usher Institute, University of Edinburgh, Edinburgh, UK; School of Health, Wellington Faculty of Health, Victoria University of Wellington, New Zealand
| | - Mauricio L Barreto
- Instituto Gonçalo Moniz, Fiocruz, Bahia, Brazil; Universidade Federal de Bahia, Salvador, Bahia, Brazil
| | | | - Manoel Barral-Netto
- Instituto Gonçalo Moniz, Fiocruz, Bahia, Brazil; Universidade Federal de Bahia, Salvador, Bahia, Brazil
| | - Aziz Sheikh
- Usher Institute, University of Edinburgh, Edinburgh, UK.
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Hitchings MD, Ranzani OT, Lind ML, Dorion M, D’Agostini TL, de Paula RC, de Paula OFP, de Moura Villela EF, Torres MSS, de Oliveira SB, Schulz W, Almiron M, Said R, de Oliveira RD, da Silva PV, de Araújo WN, Gorinchteyn JC, Dean NE, Andrews JR, Cummings DA, Ko AI, Croda J. Change in COVID-19 risk over time following vaccination with CoronaVac: A testnegative case-control study. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2021:2021.12.23.21268335. [PMID: 34988559 PMCID: PMC8728874 DOI: 10.1101/2021.12.23.21268335] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To estimate the change in odds of covid-19 over time following primary series completion of the inactivated whole virus vaccine, CoronaVac (Sinovac Biotech) in São Paulo state, Brazil. DESIGN Test negative case-control study. SETTING Community testing for covid-19 in São Paulo state, Brazil. PARTICIPANTS Adults aged 18-120 years who were residents of São Paulo state, without a previous laboratory-confirmed covid-19 infection, who received only two doses of CoronaVac, and underwent reverse transcription polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 from 17 January to 30 September 2021. MAIN OUTCOME MEASURES RT-PCR-confirmed symptomatic covid-19 and associated hospital admissions and deaths. Cases were pair-matched to test-negative controls by age (in 5-year bands), municipality of residence, healthcare worker (HCW) status, and date of RT-PCR test (±3 days). Conditional logistic regression was adjusted for sex, number of covid-19-associated comorbidities, race, and previous acute respiratory infection. RESULTS From 137,820 eligible individuals, 37,929 cases with symptomatic covid-19 and 25,756 test-negative controls with covid-19 symptoms were formed into 37,929 matched pairs. Adjusted odds ratios of symptomatic covid-19 increased with time since series completion, and this increase was greater in younger individuals, and among HCWs compared to non-HCWs. Adjusted odds ratios of covid-19 hospitalisation or death were significantly increased from 98 days since series completion, compared to individuals vaccinated 14-41 days previously: 1.40 (95% confidence interval 1.09 to 1.79) from 98-125 days, 1.55 (1.16 to 2.07) from 126-153 days, 1.56 (1.12 to 2.18) from 154-181 days, and 2.12 (1.39-3.22) from 182 days. CONCLUSIONS In the general population of São Paulo state, Brazil, an increase in odds of moderate and severe covid-19 outcomes was observed over time following primary series completion with CoronaVac.
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Affiliation(s)
- Matt D.T. Hitchings
- Department of Biostatistics, College of Public Health & Health Professions, University of Florida, Gainesville, FL, USA
| | - Otavio T. Ranzani
- Barcelona Institute for Global Health, ISGlobal, Barcelona, Spain
- Pulmonary Division, Heart Institute (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Margaret L. Lind
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Murilo Dorion
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | | | | | | | | | | | | | - Wade Schulz
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Maria Almiron
- Pan American Health Organization, Brasília, DF, Brazil
| | - Rodrigo Said
- Pan American Health Organization, Brasília, DF, Brazil
| | | | | | - Wildo Navegantes de Araújo
- Pan American Health Organization, Brasília, DF, Brazil
- Universidade de Brasília, Brasília, DF, Brazil
- National Institute for Science and Technology for Health Technology Assessment, Porto Alegre, RS, Brazil
| | | | - Natalie E. Dean
- Department of Biostatistics & Bioinformatics, Rollins School of Public Health, Emory University
| | - Jason R. Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, CA, USA
| | - Derek A.T. Cummings
- Department of Biology, University of Florida, Gainesville, FL, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Albert I. Ko
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, BA, Brazil
| | - Julio Croda
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
- Universidade Federal de Mato Grosso do Sul - UFMS, Campo Grande, MS, Brazil
- Fiocruz Mato Grosso do Sul, Fundação Oswaldo Cruz, Campo Grande, MS, Brazil
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30
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Lipsitch M, Kahn R. Interpreting vaccine efficacy trial results for infection and transmission. Vaccine 2021; 39:4082-4088. [PMID: 34130883 PMCID: PMC8197448 DOI: 10.1016/j.vaccine.2021.06.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/20/2021] [Accepted: 06/03/2021] [Indexed: 12/14/2022]
Abstract
Randomized controlled trials (RCTs) have shown high efficacy of multiple vaccines against SARS-CoV-2 disease (COVID-19), and recent studies have shown the vaccines are also effective against infection. Evidence for the effect of each of these vaccines on ability to transmit the virus is also beginning to emerge. We describe an approach to estimate these vaccines' effects on viral positivity, a prevalence measure which under the reasonable assumption that vaccinated individuals who become infected are no more infectious than unvaccinated individuals forms a lower bound on efficacy against transmission. Specifically, we recommend separate analysis of positive tests triggered by symptoms (usually the primary RCT outcome) and cross-sectional prevalence of positive tests obtained regardless of symptoms. The odds ratio of carriage for vaccine vs. placebo provides an unbiased estimate of vaccine effectiveness against viral positivity, under certain assumptions, and we show through simulations that likely departures from these assumptions will only modestly bias this estimate. Applying this approach to published data from the RCT of the Moderna vaccine, we estimate that one dose of vaccine reduces the potential for transmission by at least 61%, possibly considerably more. We describe how these approaches can be translated into observational studies of vaccine effectiveness.
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Affiliation(s)
- Marc Lipsitch
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, United States; Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, United States.
| | - Rebecca Kahn
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, United States
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31
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Patel MK, Bergeri I, Bresee JS, Cowling BJ, Crowcroft NS, Fahmy K, Hirve S, Kang G, Katz MA, Lanata CF, L'Azou Jackson M, Joshi S, Lipsitch M, Mwenda JM, Nogareda F, Orenstein WA, Ortiz JR, Pebody R, Schrag SJ, Smith PG, Srikantiah P, Subissi L, Valenciano M, Vaughn DW, Verani JR, Wilder-Smith A, Feikin DR. Evaluation of post-introduction COVID-19 vaccine effectiveness: Summary of interim guidance of the World Health Organization. Vaccine 2021; 39:4013-4024. [PMID: 34119350 PMCID: PMC8166525 DOI: 10.1016/j.vaccine.2021.05.099] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/27/2021] [Indexed: 01/07/2023]
Abstract
Phase 3 randomized-controlled trials have provided promising results of COVID-19 vaccine efficacy, ranging from 50 to 95% against symptomatic disease as the primary endpoints, resulting in emergency use authorization/listing for several vaccines. However, given the short duration of follow-up during the clinical trials, strict eligibility criteria, emerging variants of concern, and the changing epidemiology of the pandemic, many questions still remain unanswered regarding vaccine performance. Post-introduction vaccine effectiveness evaluations can help us to understand the vaccine's effect on reducing infection and disease when used in real-world conditions. They can also address important questions that were either not studied or were incompletely studied in the trials and that will inform evolving vaccine policy, including assessment of the duration of effectiveness; effectiveness in key subpopulations, such as the very old or immunocompromised; against severe disease and death due to COVID-19; against emerging SARS-CoV-2 variants of concern; and with different vaccination schedules, such as number of doses and varying dosing intervals. WHO convened an expert panel to develop interim best practice guidance for COVID-19 vaccine effectiveness evaluations. We present a summary of the interim guidance, including discussion of different study designs, priority outcomes to evaluate, potential biases, existing surveillance platforms that can be used, and recommendations for reporting results.
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Affiliation(s)
- Minal K Patel
- World Health Organization, 20 Avenue Appia, Geneva 1211, Switzerland.
| | - Isabel Bergeri
- World Health Organization, 20 Avenue Appia, Geneva 1211, Switzerland
| | - Joseph S Bresee
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA, USA
| | - Benjamin J Cowling
- School of Public Health, The University of Hong Kong, Pokfulam, Hong Kong, China
| | | | - Kamal Fahmy
- World Health Organization Regional Office for the Eastern Mediterranean, Monazamet El Seha El Alamia Str, Extension of Abdel Razak El Sanhouri Street, P.O. Box 7608, Nasr City, Cairo 11371, Egypt
| | | | - Gagandeep Kang
- Christian Medical College, Ida Scudder Road, Vellore, Tamil Nadu 632004, India
| | - Mark A Katz
- World Health Organization Regional Office of Europe, UN City, Marmorvej 51, Copenhagen DK-2100, Denmark
| | - Claudio F Lanata
- Instituto de Investigación Nutricional, Av. la Molina 1885, La Molina 15024, Peru
| | - Maïna L'Azou Jackson
- The Coalition for Epidemic Preparedness Innovations (CEPI), Gibbs building, 215 Euston Rd, Bloomsbury, London NW1 2BE, United Kingdom
| | - Sudhir Joshi
- World Health Organization Regional Office for South-East Asia, World Health House, Indraprastha Estate, Mahatma Gandhi Marg, New Delhi 110 002, India
| | - Marc Lipsitch
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Jason M Mwenda
- World Health Organization Regional Office for Africa, Cité du Djoué, P.O. Box 06, Brazzaville, Republic of Congo
| | - Francisco Nogareda
- Consultant to the Pan American Health Organization, 525 23rd Street NW, Washington, DC 20037, USA
| | | | - Justin R Ortiz
- Center for Vaccine Development & Global Health, University of Maryland School of Medicine, 685 W. Baltimore St., Room #480, Baltimore, MD 21201, USA
| | - Richard Pebody
- World Health Organization Regional Office of Europe, UN City, Marmorvej 51, Copenhagen DK-2100, Denmark
| | - Stephanie J Schrag
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA, USA
| | - Peter G Smith
- MRC International Epidemiology & Statistics Group, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | | | - Lorenzo Subissi
- World Health Organization, 20 Avenue Appia, Geneva 1211, Switzerland
| | | | - David W Vaughn
- Bill & Melinda Gates Foundation, 500 5th Ave N., Seattle, WA 98109, USA
| | - Jennifer R Verani
- U.S. Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA, USA
| | | | - Daniel R Feikin
- World Health Organization, 20 Avenue Appia, Geneva 1211, Switzerland
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Lipsitch M, Kahn R. Interpreting vaccine efficacy trial results for infection and transmission. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2021:2021.02.25.21252415. [PMID: 33655276 PMCID: PMC7924301 DOI: 10.1101/2021.02.25.21252415] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Randomized controlled trials (RCTs) have shown high efficacy of multiple vaccines against SARS-CoV-2 disease (COVID-19), and recent studies have shown the vaccines are also effective against infection. Evidence for the effect of each of these vaccines on ability to transmit the virus is also beginning to emerge. We describe an approach to estimate these vaccines' effects on viral positivity, a prevalence measure which under the reasonable assumption that vaccinated individuals who become infected are no more infectious than unvaccinated individuals forms a lower bound on efficacy against transmission. Specifically, we recommend separate analysis of positive tests triggered by symptoms (usually the primary outcome) and cross-sectional prevalence of positive tests obtained regardless of symptoms. The odds ratio of carriage for vaccine vs. placebo provides an unbiased estimate of vaccine effectiveness against viral positivity, under certain assumptions, and we show through simulations that likely departures from these assumptions will only modestly bias this estimate. Applying this approach to published data from the RCT of the Moderna vaccine, we estimate that one dose of vaccine reduces the potential for transmission by at least 61%, possibly considerably more. We describe how these approaches can be translated into observational studies of vaccine effectiveness.
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Affiliation(s)
- Marc Lipsitch
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
| | - Rebecca Kahn
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
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Dagan N, Barda N, Kepten E, Miron O, Perchik S, Katz MA, Hernán MA, Lipsitch M, Reis B, Balicer RD. BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting. N Engl J Med 2021; 384:1412-1423. [PMID: 33626250 PMCID: PMC7944975 DOI: 10.1056/nejmoa2101765] [Citation(s) in RCA: 1743] [Impact Index Per Article: 581.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND As mass vaccination campaigns against coronavirus disease 2019 (Covid-19) commence worldwide, vaccine effectiveness needs to be assessed for a range of outcomes across diverse populations in a noncontrolled setting. In this study, data from Israel's largest health care organization were used to evaluate the effectiveness of the BNT162b2 mRNA vaccine. METHODS All persons who were newly vaccinated during the period from December 20, 2020, to February 1, 2021, were matched to unvaccinated controls in a 1:1 ratio according to demographic and clinical characteristics. Study outcomes included documented infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), symptomatic Covid-19, Covid-19-related hospitalization, severe illness, and death. We estimated vaccine effectiveness for each outcome as one minus the risk ratio, using the Kaplan-Meier estimator. RESULTS Each study group included 596,618 persons. Estimated vaccine effectiveness for the study outcomes at days 14 through 20 after the first dose and at 7 or more days after the second dose was as follows: for documented infection, 46% (95% confidence interval [CI], 40 to 51) and 92% (95% CI, 88 to 95); for symptomatic Covid-19, 57% (95% CI, 50 to 63) and 94% (95% CI, 87 to 98); for hospitalization, 74% (95% CI, 56 to 86) and 87% (95% CI, 55 to 100); and for severe disease, 62% (95% CI, 39 to 80) and 92% (95% CI, 75 to 100), respectively. Estimated effectiveness in preventing death from Covid-19 was 72% (95% CI, 19 to 100) for days 14 through 20 after the first dose. Estimated effectiveness in specific subpopulations assessed for documented infection and symptomatic Covid-19 was consistent across age groups, with potentially slightly lower effectiveness in persons with multiple coexisting conditions. CONCLUSIONS This study in a nationwide mass vaccination setting suggests that the BNT162b2 mRNA vaccine is effective for a wide range of Covid-19-related outcomes, a finding consistent with that of the randomized trial.
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Affiliation(s)
- Noa Dagan
- From the Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv (N.D., N.B., E.K., O.M., S.P., M.A.K., R.D.B.), and the School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Be'er Sheva (O.M., M.A.K., R.D.B.) - both in Israel; University of Michigan School of Public Health, Ann Arbor (M.A.K.); and the Department of Biomedical Informatics (N.D., N.B.), Harvard Medical School (B.R.), the Departments of Epidemiology and Biostatistics (M.A.H.), and the Center for Communicable Disease Dynamics, Departments of Epidemiology and of Immunology and Infectious Diseases (M.L.), Harvard T.H. Chan School of Public Health, Harvard-MIT Division of Health Sciences and Technology (M.A.H.), and the Predictive Medicine Group, Computational Health Informatics Program, Boston Children's Hospital (B.R.) - all in Boston
| | - Noam Barda
- From the Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv (N.D., N.B., E.K., O.M., S.P., M.A.K., R.D.B.), and the School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Be'er Sheva (O.M., M.A.K., R.D.B.) - both in Israel; University of Michigan School of Public Health, Ann Arbor (M.A.K.); and the Department of Biomedical Informatics (N.D., N.B.), Harvard Medical School (B.R.), the Departments of Epidemiology and Biostatistics (M.A.H.), and the Center for Communicable Disease Dynamics, Departments of Epidemiology and of Immunology and Infectious Diseases (M.L.), Harvard T.H. Chan School of Public Health, Harvard-MIT Division of Health Sciences and Technology (M.A.H.), and the Predictive Medicine Group, Computational Health Informatics Program, Boston Children's Hospital (B.R.) - all in Boston
| | - Eldad Kepten
- From the Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv (N.D., N.B., E.K., O.M., S.P., M.A.K., R.D.B.), and the School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Be'er Sheva (O.M., M.A.K., R.D.B.) - both in Israel; University of Michigan School of Public Health, Ann Arbor (M.A.K.); and the Department of Biomedical Informatics (N.D., N.B.), Harvard Medical School (B.R.), the Departments of Epidemiology and Biostatistics (M.A.H.), and the Center for Communicable Disease Dynamics, Departments of Epidemiology and of Immunology and Infectious Diseases (M.L.), Harvard T.H. Chan School of Public Health, Harvard-MIT Division of Health Sciences and Technology (M.A.H.), and the Predictive Medicine Group, Computational Health Informatics Program, Boston Children's Hospital (B.R.) - all in Boston
| | - Oren Miron
- From the Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv (N.D., N.B., E.K., O.M., S.P., M.A.K., R.D.B.), and the School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Be'er Sheva (O.M., M.A.K., R.D.B.) - both in Israel; University of Michigan School of Public Health, Ann Arbor (M.A.K.); and the Department of Biomedical Informatics (N.D., N.B.), Harvard Medical School (B.R.), the Departments of Epidemiology and Biostatistics (M.A.H.), and the Center for Communicable Disease Dynamics, Departments of Epidemiology and of Immunology and Infectious Diseases (M.L.), Harvard T.H. Chan School of Public Health, Harvard-MIT Division of Health Sciences and Technology (M.A.H.), and the Predictive Medicine Group, Computational Health Informatics Program, Boston Children's Hospital (B.R.) - all in Boston
| | - Shay Perchik
- From the Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv (N.D., N.B., E.K., O.M., S.P., M.A.K., R.D.B.), and the School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Be'er Sheva (O.M., M.A.K., R.D.B.) - both in Israel; University of Michigan School of Public Health, Ann Arbor (M.A.K.); and the Department of Biomedical Informatics (N.D., N.B.), Harvard Medical School (B.R.), the Departments of Epidemiology and Biostatistics (M.A.H.), and the Center for Communicable Disease Dynamics, Departments of Epidemiology and of Immunology and Infectious Diseases (M.L.), Harvard T.H. Chan School of Public Health, Harvard-MIT Division of Health Sciences and Technology (M.A.H.), and the Predictive Medicine Group, Computational Health Informatics Program, Boston Children's Hospital (B.R.) - all in Boston
| | - Mark A Katz
- From the Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv (N.D., N.B., E.K., O.M., S.P., M.A.K., R.D.B.), and the School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Be'er Sheva (O.M., M.A.K., R.D.B.) - both in Israel; University of Michigan School of Public Health, Ann Arbor (M.A.K.); and the Department of Biomedical Informatics (N.D., N.B.), Harvard Medical School (B.R.), the Departments of Epidemiology and Biostatistics (M.A.H.), and the Center for Communicable Disease Dynamics, Departments of Epidemiology and of Immunology and Infectious Diseases (M.L.), Harvard T.H. Chan School of Public Health, Harvard-MIT Division of Health Sciences and Technology (M.A.H.), and the Predictive Medicine Group, Computational Health Informatics Program, Boston Children's Hospital (B.R.) - all in Boston
| | - Miguel A Hernán
- From the Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv (N.D., N.B., E.K., O.M., S.P., M.A.K., R.D.B.), and the School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Be'er Sheva (O.M., M.A.K., R.D.B.) - both in Israel; University of Michigan School of Public Health, Ann Arbor (M.A.K.); and the Department of Biomedical Informatics (N.D., N.B.), Harvard Medical School (B.R.), the Departments of Epidemiology and Biostatistics (M.A.H.), and the Center for Communicable Disease Dynamics, Departments of Epidemiology and of Immunology and Infectious Diseases (M.L.), Harvard T.H. Chan School of Public Health, Harvard-MIT Division of Health Sciences and Technology (M.A.H.), and the Predictive Medicine Group, Computational Health Informatics Program, Boston Children's Hospital (B.R.) - all in Boston
| | - Marc Lipsitch
- From the Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv (N.D., N.B., E.K., O.M., S.P., M.A.K., R.D.B.), and the School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Be'er Sheva (O.M., M.A.K., R.D.B.) - both in Israel; University of Michigan School of Public Health, Ann Arbor (M.A.K.); and the Department of Biomedical Informatics (N.D., N.B.), Harvard Medical School (B.R.), the Departments of Epidemiology and Biostatistics (M.A.H.), and the Center for Communicable Disease Dynamics, Departments of Epidemiology and of Immunology and Infectious Diseases (M.L.), Harvard T.H. Chan School of Public Health, Harvard-MIT Division of Health Sciences and Technology (M.A.H.), and the Predictive Medicine Group, Computational Health Informatics Program, Boston Children's Hospital (B.R.) - all in Boston
| | - Ben Reis
- From the Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv (N.D., N.B., E.K., O.M., S.P., M.A.K., R.D.B.), and the School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Be'er Sheva (O.M., M.A.K., R.D.B.) - both in Israel; University of Michigan School of Public Health, Ann Arbor (M.A.K.); and the Department of Biomedical Informatics (N.D., N.B.), Harvard Medical School (B.R.), the Departments of Epidemiology and Biostatistics (M.A.H.), and the Center for Communicable Disease Dynamics, Departments of Epidemiology and of Immunology and Infectious Diseases (M.L.), Harvard T.H. Chan School of Public Health, Harvard-MIT Division of Health Sciences and Technology (M.A.H.), and the Predictive Medicine Group, Computational Health Informatics Program, Boston Children's Hospital (B.R.) - all in Boston
| | - Ran D Balicer
- From the Clalit Research Institute, Innovation Division, Clalit Health Services, Tel Aviv (N.D., N.B., E.K., O.M., S.P., M.A.K., R.D.B.), and the School of Public Health, Faculty of Health Sciences, Ben Gurion University of the Negev, Be'er Sheva (O.M., M.A.K., R.D.B.) - both in Israel; University of Michigan School of Public Health, Ann Arbor (M.A.K.); and the Department of Biomedical Informatics (N.D., N.B.), Harvard Medical School (B.R.), the Departments of Epidemiology and Biostatistics (M.A.H.), and the Center for Communicable Disease Dynamics, Departments of Epidemiology and of Immunology and Infectious Diseases (M.L.), Harvard T.H. Chan School of Public Health, Harvard-MIT Division of Health Sciences and Technology (M.A.H.), and the Predictive Medicine Group, Computational Health Informatics Program, Boston Children's Hospital (B.R.) - all in Boston
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Abstract
Influenza vaccine effectiveness (VE) wanes over the course of a temperate climate winter season but little data are available from tropical countries with year-round influenza virus activity. In Singapore, a retrospective cohort study of adults vaccinated from 2013 to 2017 was conducted. Influenza vaccine failure was defined as hospital admission with polymerase chain reaction-confirmed influenza infection 2–49 weeks after vaccination. Relative VE was calculated by splitting the follow-up period into 8-week episodes (Lexis expansion) and the odds of influenza infection in the first 8-week period after vaccination (weeks 2–9) compared with subsequent 8-week periods using multivariable logistic regression adjusting for patient factors and influenza virus activity. Records of 19 298 influenza vaccinations were analysed with 617 (3.2%) influenza infections. Relative VE was stable for the first 26 weeks post-vaccination, but then declined for all three influenza types/subtypes to 69% at weeks 42–49 (95% confidence interval (CI) 52–92%, P = 0.011). VE declined fastest in older adults, in individuals with chronic pulmonary disease and in those who had been previously vaccinated within the last 2 years. Vaccine failure was significantly associated with a change in recommended vaccine strains between vaccination and observation period (adjusted odds ratio 1.26, 95% CI 1.06–1.50, P = 0.010).
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