1
|
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.
Collapse
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
| |
Collapse
|
2
|
Jones RP, Ponomarenko A. Roles for Pathogen Interference in Influenza Vaccination, with Implications to Vaccine Effectiveness (VE) and Attribution of Influenza Deaths. Infect Dis Rep 2022; 14:710-758. [PMID: 36286197 PMCID: PMC9602062 DOI: 10.3390/idr14050076] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/15/2022] [Accepted: 09/15/2022] [Indexed: 08/29/2023] Open
Abstract
Pathogen interference is the ability of one pathogen to alter the course and clinical outcomes of infection by another. With up to 3000 species of human pathogens the potential combinations are vast. These combinations operate within further immune complexity induced by infection with multiple persistent pathogens, and by the role which the human microbiome plays in maintaining health, immune function, and resistance to infection. All the above are further complicated by malnutrition in children and the elderly. Influenza vaccination offers a measure of protection for elderly individuals subsequently infected with influenza. However, all vaccines induce both specific and non-specific effects. The specific effects involve stimulation of humoral and cellular immunity, while the nonspecific effects are far more nuanced including changes in gene expression patterns and production of small RNAs which contribute to pathogen interference. Little is known about the outcomes of vaccinated elderly not subsequently infected with influenza but infected with multiple other non-influenza winter pathogens. In this review we propose that in certain years the specific antigen mix in the seasonal influenza vaccine inadvertently increases the risk of infection from other non-influenza pathogens. The possibility that vaccination could upset the pathogen balance, and that the timing of vaccination relative to the pathogen balance was critical to success, was proposed in 2010 but was seemingly ignored. Persons vaccinated early in the winter are more likely to experience higher pathogen interference. Implications to the estimation of vaccine effectiveness and influenza deaths are discussed.
Collapse
Affiliation(s)
- Rodney P Jones
- Healthcare Analysis and Forecasting, Wantage OX12 0NE, UK
| | - Andrey Ponomarenko
- Department of Biophysics, Informatics and Medical Instrumentation, Odessa National Medical University, Valikhovsky Lane 2, 65082 Odessa, Ukraine
| |
Collapse
|
3
|
Yao TC, Wu AC, Tsai HJ. Validation of the Association of Oral Corticosteroid Bursts With Adverse Events in Children-Reply. JAMA Pediatr 2021; 175:1187. [PMID: 34424284 DOI: 10.1001/jamapediatrics.2021.2815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Tsung-Chieh Yao
- Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan.,School of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Ann Chen Wu
- Center for Healthcare Research in Pediatrics, Department of Population Medicine, Harvard Pilgrim Health Care Institute and Harvard Medical School, Boston, Massachusetts.,Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts
| | - Hui-Ju Tsai
- Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Taiwan
| |
Collapse
|
4
|
Papaioannou A, Konstantinidi AE, Primikiri E, Asimakopoulou F, Aravantinos D, Mavromichali Z. Influenza vaccination rate among high risk group patients in primary health care in Greece. Cent Eur J Public Health 2021; 28:297-301. [PMID: 33338366 DOI: 10.21101/cejph.a5237] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 08/11/2020] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Seasonal influenza vaccination is the main method for influenza prevention. The main objective of this study is to estimate the frequency of vaccinations in patients with chronic illnesses presented to a primary health care (PHC) centre. METHODS This cross-sectional study was performed in patients admitted to the Kapandriti Health Centre. Their vaccination status with an influenza vaccine and their underlying diseases were recorded. RESULTS 34.8% of the subjects had been vaccinated against seasonal influenza. Vaccination coverage was found to be 53.9% in pulmonary, 55.6% in chronic kidney disease, 43.7% in cardiovascular disorders, 40.6% in diabetes, 40.6% in any kind of malignancy, and finally 33.3% in neurological patients. The most significant predictors for vaccination were the age group of 60 to 79 years (OR = 3.08, 95% CI: 1.79-5.29), age over 80 years (OR = 2.91, 95% CI: 1.58-5.36), respiratory disease (OR = 2.25, 95% CI: 1.33-3.76), cardiovascular disorder (OR = 1.46, 95% CI: 1.02-2.10), and 3 to 5 visits to the unit annually (OR = 1.57, 95% CI: 1.12-2.24). Finally, it was discovered that coexistence of one to three diseases reduced the likelihood ratio for vaccine uptake (OR = 0.15, 95% CI: 0.03-0.79, p < 0.05). CONCLUSIONS The influenza vaccination rate for the population of the present study has been found higher than that reported previously in literature. We believe that there is a need to implement new and more effective strategies such as educating vulnerable groups on the benefits of vaccination and so reducing the incidence of influenza and its complications especially in vulnerable groups.
Collapse
Affiliation(s)
- Anastasia Papaioannou
- Health Centre of Nea Makri, Athens, Greece.,Health Centre of Kapandriti, Athens, Greece
| | | | | | | | | | | |
Collapse
|
5
|
Tsuzuki S, Ishikane M, Matsunaga N, Morioka S, Yu J, Inagaki T, Yamamoto M, Ohmagari N. Interim 2019/2020 Influenza Vaccine Effectiveness in Japan from October 2019 to January 2020. Jpn J Infect Dis 2020; 74:175-179. [PMID: 32999182 DOI: 10.7883/yoken.jjid.2020.177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Herein, we report the interim vaccine effectiveness (VE) of a quadrivalent inactivated influenza vaccine, during the 2019/2020 influenza season, in Japan. We conducted a retrospective observational cohort study of 381 patients aged ≥15 years, who were enrolled with influenza like illnesses and examined via the rapid influenza diagnostic test, at the Ambulatory Care unit of the National Center for Global Health and Medicine in Tokyo, Japan, from the beginning of October 2019 to the end of January 2020. VE was estimated using a test-negative design. VE was calculated as (1 - odds ratio) × 100%, comparing influenza A test positivity between vaccinated and unvaccinated patients. Of the 381 patients initially screened for inclusion, 314 were enrolled in the study. Of these, 105 were vaccinated, 98 were diagnosed with influenza A, and 5 were diagnosed with influenza B. Overall VE against influenza A was 27.6% (95% confidence interval [CI], ‒21.1 to +57.4), and in patients aged ≥65 years, it was 47.3% (95% CI, ‒76.0 to +86.0). This indicates that the influenza vaccination offered continued protection during the 2019/2020 influenza season, but a detailed analysis of more cases with a careful consideration of methodology is necessary to estimate VE more precisely.
Collapse
Affiliation(s)
- Shinya Tsuzuki
- AMR Clinical Reference Center, National Center for Global Health and Medicine, Japan.,Faculty of Medicine and Health Sciences, University of Antwerp, Belgium
| | - Masahiro Ishikane
- AMR Clinical Reference Center, National Center for Global Health and Medicine, Japan.,Disease Control and Prevention Center, National Center for Global Health and Medicine, Japan
| | - Nobuaki Matsunaga
- AMR Clinical Reference Center, National Center for Global Health and Medicine, Japan
| | - Shinichiro Morioka
- Disease Control and Prevention Center, National Center for Global Health and Medicine, Japan
| | - Jiefu Yu
- AMR Clinical Reference Center, National Center for Global Health and Medicine, Japan.,Disease Control and Prevention Center, National Center for Global Health and Medicine, Japan
| | - Takeshi Inagaki
- General Internal Medicine, National Center for Global Health and Medicine, Japan.,Department of Emergency Medicine and Critical Care, National Center for Global Health and Medicine, Japan
| | - Makiko Yamamoto
- Department of Emergency Medicine and Critical Care, National Center for Global Health and Medicine, Japan
| | - Norio Ohmagari
- AMR Clinical Reference Center, National Center for Global Health and Medicine, Japan.,Disease Control and Prevention Center, National Center for Global Health and Medicine, Japan
| |
Collapse
|
6
|
Meng Z, Zhang J, Shi J, Zhao W, Huang X, Cheng L, Yang X. Immunogenicity of influenza vaccine in elderly people: a systematic review and meta-analysis of randomized controlled trials, and its association with real-world effectiveness. Hum Vaccin Immunother 2020; 16:2680-2689. [PMID: 32347787 PMCID: PMC7746244 DOI: 10.1080/21645515.2020.1747375] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Background: Older people (≥60 years old) are particularly vulnerable to influenza virus infection, and vaccine is effective in reducing the disease burden in this population. However, it remains obscure whether their antibody response is lower than those of younger adults (18–60 years old). Thus, this meta-analysis was performed to compare the immunogenicity of influenza vaccines and understand their association with real-world vaccine effectiveness (VE) between these two age groups. Methods: A systematic literature search was conducted to identify relevant studies from Jan 01, 2008 to Nov 10, 2018. These are randomized controlled trials that included older adult samples, which assessed the immunogenicity of inactivated quadrivalent influenza vaccines produced in embryonated eggs. We excluded the studies focused only in children or adults. The outcomes were seroprotecton rate (SPR) and seroconversion rate (SCR). Results: Six studies were eventually included in the present meta-analysis (7,976 participants). For the SPR, the pooled risk ratio (RR) was 0.92 (95% CI: 0.90–0.94, I2 = 66%, P < .0001) for A/H1N1 and 0.94 (95% CI: 0.90–0.98, I2 = 91%, P = .002) for B/Victoria, and the antibody responses of A/H3N2 and B/Yamagata were similar in the two age groups. For the SCR, the pooled RR was 0.85 (95% CI: 0.76–0.94, I2 = 93%, P = .003), 0.77 (95% CI: 0.66–0.91, I2 = 94%, P = .002), and 0.83 (95% CI: 0.71–0.96, I2 = 94%, P = .02) for A/H1N1, B/Victoria and B/Yamagata, respectively, and the antibody responses of A/H3N2 were similar in the two groups. Some variations were found in the antibody responses across virus types and subtypes after influenza vaccination. Conclusion: The SPR and SCR of older adults were lower than those in younger adults for A/H1N1 and B/Victoria, while the two age groups had similar antibody responses for A/H3N2. The antibody responses to vaccines were not significantly associated with real-world VE, indicating that antibody response might not fully reflect the vaccine effectiveness of A/H3N2.
Collapse
Affiliation(s)
- Ziyan Meng
- National Institute of Engineering Technology Research in Combination Vaccines , Wuhan, China.,Wuhan Institute of Biological Products 430207 , Wuhan, China
| | - Jiayou Zhang
- National Institute of Engineering Technology Research in Combination Vaccines , Wuhan, China.,Wuhan Institute of Biological Products 430207 , Wuhan, China
| | - Jinrong Shi
- National Institute of Engineering Technology Research in Combination Vaccines , Wuhan, China.,Wuhan Institute of Biological Products 430207 , Wuhan, China
| | - Wei Zhao
- National Institute of Engineering Technology Research in Combination Vaccines , Wuhan, China.,Wuhan Institute of Biological Products 430207 , Wuhan, China
| | - Xiaoyuan Huang
- National Institute of Engineering Technology Research in Combination Vaccines , Wuhan, China.,Wuhan Institute of Biological Products 430207 , Wuhan, China
| | - Li Cheng
- Center for Evaluation and Inspection of Hubei Food and Drug Administration , Wuhan, China
| | - Xiaoming Yang
- National Institute of Engineering Technology Research in Combination Vaccines , Wuhan, China.,China National Biotech Group Company Limited , Beijing, China
| |
Collapse
|
7
|
Tsuzuki S, Baguelin M, Pebody R, van Leeuwen E. Modelling the optimal target age group for seasonal influenza vaccination in Japan. Vaccine 2019; 38:752-762. [PMID: 31735503 DOI: 10.1016/j.vaccine.2019.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 10/25/2019] [Accepted: 11/01/2019] [Indexed: 01/04/2023]
Abstract
BACKGROUND In Japan, the current influenza vaccination programme is targeting older individuals. On the other hand, epidemics of influenza are likely to be mainly driven by children. In this study, we consider the most cost-effective target age group for a seasonal influenza vaccination programme in Japan. METHODS We constructed a deterministic compartmental Susceptible-Exposed-Infectious-Recovered (SEIR) model with data from the 2012/13 to 2014/15 influenza seasons in Japan. Bayesian inference with Markov Chain Monte Carlo method was used for parameter estimation. Cost-effectiveness analyses were conducted from public health care payer's perspective. RESULTS A scenario targeting children under 15 was expected to reduce the number of cases 6,382,345 compared to the current strategy. A scenario targeting elderly population (age over 49 years) was expected to reduce the number of cases 693,206. The children targeted scenario demonstrated negative ICER (incremental cost-effectiveness ratio) value. On the other hand, elderly targeted scenario demonstrated higher ICER value than the willingness to pay (50,000 USD/QALY). CONCLUSIONS A vaccination programme which targets children under 15 is predicted to have much larger epidemiological impact than those targeting elderly.
Collapse
Affiliation(s)
- Shinya Tsuzuki
- Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan; Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; Respiratory Diseases Department, Public Health England, London, United Kingdom.
| | - Marc Baguelin
- Respiratory Diseases Department, Public Health England, London, United Kingdom; MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, W2 1PG, United Kingdom; Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Richard Pebody
- Respiratory Diseases Department, Public Health England, London, United Kingdom
| | - Edwin van Leeuwen
- Respiratory Diseases Department, Public Health England, London, United Kingdom
| |
Collapse
|
8
|
Impact of influenza vaccination on healthcare utilization - A systematic review. Vaccine 2019; 37:3179-3189. [PMID: 31047677 DOI: 10.1016/j.vaccine.2019.04.051] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 04/11/2019] [Accepted: 04/12/2019] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Although a vaccine-preventable disease, influenza causes approximately 3-5 million cases of severe illness and about 290,000-650,000 deaths worldwide, which occur primarily among people 65 years and older. Nonetheless, prevention of influenza and its complications rely mainly on vaccination. We aimed to systematically evaluate influenza vaccine effectiveness at reducing healthcare utilization in older adults, defined as the reduction of outpatient visits, ILI and influenza hospitalizations, utilization of antibiotics and cardiovascular events by vaccination status during the influenza season. METHODS We searched MEDLINE, EMBASE, CINAHL, Cochrane Library and considered any seasonal influenza vaccine, excluding the pandemic (2009-10 season) vaccine. Reviewers independently assessed data extraction and quality assessment. RESULTS Of the 8308 citations retrieved, 22 studies were included in the systematic review. Overall, two studies (9%) were deemed at moderate risk of bias, thirteen (59%) at serious risk of bias and seven (32%) at critical risk of bias. For outpatient visits, we found modest evidence of protection by the influenza vaccine. For all-cause hospitalization outcomes, we found a wide range of results, mostly deemed at serious risk of bias. The included studies suggested that the vaccine may protect older adults against influenza hospitalizations and cardiovascular events. No article meeting our inclusion criteria explored the use of antibiotics and ILI hospitalizations. The high heterogeneity between studies hindered the aggregation of data into a meta-analysis. CONCLUSION The variability between studies prevented us from drawing a clear conclusion on the effectiveness of the influenza vaccine on healthcare utilization in older adults. Overall, the data suggests that the vaccine may result in a reduction of healthcare utilization in the older population. Further studies of higher quality are necessary.
Collapse
|
9
|
Baum U, Auranen K, Kulathinal S, Syrjänen R, Nohynek H, Jokinen J. Cohort study design for estimating the effectiveness of seasonal influenza vaccines in real time based on register data: The Finnish example. Scand J Public Health 2018; 48:316-322. [PMID: 30387371 DOI: 10.1177/1403494818808635] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This paper presents the principles of implementing register-based cohort studies as currently applied for real-time estimation of influenza vaccine effectiveness in Finland. All required information is retrieved from computerised national registers and deterministically linked via the unique personal identity code assigned to each Finnish resident. The study cohorts comprise large subpopulations eligible for a free seasonal influenza vaccination as part of the National Vaccination Programme. The primary outcome is laboratory-confirmed influenza. Each study subject is taken to be at risk of experiencing the outcome from the onset of the influenza season until the first of the following three events occurs: outcome, loss to follow up or end of season. Seasonal influenza vaccination is viewed as time-dependent exposure. Accordingly, each subject may contribute unvaccinated and vaccinated person-time during their time at risk. The vaccine effectiveness is estimated as one minus the influenza incidence rate ratio comparing the vaccinated with the unvaccinated within the study cohorts. Data collection in register-based research is an almost fully automated process. The effort, resources and the time spent in the field are relatively small compared to other observational study designs. This advantage is pivotal when vaccine effectiveness estimates are needed in real time. The paper outlines possible limitations of register-based cohort studies. It also addresses the need to explore how national and subnational registers available in the Nordic countries and elsewhere can be utilised in vaccine effectiveness research to guide decision making and to improve individual health as well as public health.
Collapse
Affiliation(s)
- Ulrike Baum
- Department of Public Health Solutions, National Institute for Health and Welfare, Finland.,Doctoral Programme in Clinical Research, University of Turku, Finland
| | - Kari Auranen
- Department of Mathematics and Statistics, University of Turku, Finland.,Department of Clinical Medicine, University of Turku, Finland
| | - Sangita Kulathinal
- Department of Information Services, National Institute for Health and Welfare, Finland
| | - Ritva Syrjänen
- Department of Public Health Solutions, National Institute for Health and Welfare, Finland
| | - Hanna Nohynek
- Department of Health Security, National Institute for Health and Welfare, Finland
| | - Jukka Jokinen
- Department of Public Health Solutions, National Institute for Health and Welfare, Finland
| |
Collapse
|
10
|
Influenza vaccine showed a good preventive effect against influenza-associated hospitalization among elderly patients, during the 2016/17 season in Japan. J Infect Chemother 2018; 24:873-880. [PMID: 30100400 DOI: 10.1016/j.jiac.2018.07.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/28/2018] [Accepted: 07/18/2018] [Indexed: 01/09/2023]
Abstract
The 2016/17 influenza season in Japan was characterized by a predominance of influenza A (H3N2) activity; with H3N2 accounting for 85% of all detected influenza virus infections. We assessed the vaccine effectiveness (VE) of an inactivated quadrivalent influenza vaccine (IIV4) in adult patients, using a test-negative case-control design study based on the results of a rapid influenza diagnostic test (RIDT). Between November 2016 and March 2017, a total of 1048 adult patients were enrolled: including 363 RIDT positive for influenza A, 9 RIDT-positive for influenza B, and 676 RIDT-negative. During the 2016/17 season, the overall adjusted VE was 28.8% (95% confidence interval [CI]: 6.3-46%). The adjusted VE against influenza A was 27.4% (95%CI: 4.4-45%). The VE against influenza B could not be estimated because of the very low number of influenza B patients. Twenty-nine patients were hospitalized due to influenza-associated illness-during the present study, all of whom were infected with influenza A virus. The adjusted VE, determined using a case-control study, for preventing hospitalization for influenza A infection was 72.6% (95%CI: 30.7-89.1%). In addition, the VE for preventing hospitalization of influenza patients with comorbidities was 78.2% (95%CI: 41.1-92%). Our study showed that, during the 2016/17season, IIV4 was effective for preventing both the onset of influenza and influenza-associated hospitalization.
Collapse
|
11
|
Shibata N, Kimura S, Hoshino T, Takeuchi M, Urushihara H. Effectiveness of influenza vaccination for children in Japan: Four-year observational study using a large-scale claims database. Vaccine 2018; 36:2809-2815. [DOI: 10.1016/j.vaccine.2018.03.082] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Revised: 02/26/2018] [Accepted: 03/29/2018] [Indexed: 12/25/2022]
|
12
|
Jermacane D, Gobin M, Young N, Yates J, Owusu GO. An outbreak of acute respiratory illnesses in primary school children with low vaccine uptake, UK, 2016. Vaccine 2017; 35:5527-5530. [DOI: 10.1016/j.vaccine.2017.07.106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/30/2017] [Accepted: 07/27/2017] [Indexed: 10/18/2022]
|
13
|
Seki Y, Onose A, Sugaya N. Influenza vaccine effectiveness in adults based on the rapid influenza diagnostic test results, during the 2015/16 season. J Infect Chemother 2017; 23:615-620. [PMID: 28668446 DOI: 10.1016/j.jiac.2017.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/11/2017] [Accepted: 06/01/2017] [Indexed: 10/19/2022]
Abstract
We assessed the influenza vaccine effectiveness (VE) of an inactivated quadrivalent influenza vaccine in adult patients, in our test-negative case-control design study based on the results of a rapid influenza diagnostic test. During the 2015/16 season in Japan, influenza A(H1N1)pdm09 virus and influenza B virus were epidemic. The overall adjusted VE was 44% (95% confidence interval [CI]: 13.6%-63.7%). The adjusted VE was 52.9% (95%CI: 20%-72.3%) against any influenza virus among those < 65 years of age and -5% (95%CI: 136%-53.5%) among the elderly ≧ 65 years of age. The adjusted VE against influenza A was 49.1% (95%CI: 13.9%-69.9%). Although the VE was 55.5% (95%CI: 14.8%-76.8%) among those <65 years of age, it was only 15.3% (95%CI: 120%-67.4%) among the elderly ≧ 65 years of age. The adjusted VE against influenza B was 33.8% (95%CI: 25%-64.8%) among adult patients (≧16 years of age) and 46.8% (95%CI: 13%-75%) among those < 65 years of age, the VE against influenza B could not be estimated in those ≧65 years of age because of the low number of elderly patients with that virus.
Collapse
Affiliation(s)
- Yuki Seki
- Department of Internal Medicine, Keiyu Hospital, Japan.
| | - Akira Onose
- Department of Internal Medicine, Nanashima Clinic, Japan
| | | |
Collapse
|
14
|
Hergens MP, Baum U, Brytting M, Ikonen N, Haveri A, Wiman Å, Nohynek H, Örtqvist Å. Mid-season real-time estimates of seasonal influenza vaccine effectiveness in persons 65 years and older in register-based surveillance, Stockholm County, Sweden, and Finland, January 2017. ACTA ACUST UNITED AC 2017; 22:30469. [PMID: 28251891 PMCID: PMC5356437 DOI: 10.2807/1560-7917.es.2017.22.8.30469] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 02/20/2017] [Indexed: 01/03/2023]
Abstract
Systems for register-based monitoring of vaccine effectiveness (VE) against laboratory-confirmed influenza (LCI) in real time were set up in Stockholm County, Sweden, and Finland, before start of the 2016/17 influenza season, using population-based cohort studies. Both in Stockholm and Finland, an early epidemic of influenza A(H3N2) peaked in week 52, 2016. Already during weeks 48 to 50, analyses of influenza VE in persons 65 years and above showed moderately good estimates of around 50%, then rapidly declined by week 2, 2017 to 28% and 32% in Stockholm and Finland, respectively. The sensitivity analyses, where time since vaccination was taken into account, could not demonstrate a clear decline, neither by calendar week nor by time since vaccination. Most (68%) of the samples collected from vaccinated patients belonged to the 3C.2a1 subclade with the additional amino acid substitution T135K in haemagglutinin (64%) or to subclade 3C.2a with the additional haemagglutinin substitutions T131K and R142K (36%). The proportion of samples containing these alterations increased during the studied period. These substitutions may be responsible for viral antigenic change and part of the observed VE drop. Another possible cause is poor vaccine immunogenicity in older persons. Improved influenza vaccines are needed, especially for the elderly.
Collapse
Affiliation(s)
- Maria-Pia Hergens
- Department of Communicable Disease Control and Prevention, Stockholm County Council, and Karolinska Institutet, Department of Medicine Karolinska Solna, Unit of Infectious Diseases, Stockholm, Sweden.,These authors contributed equally to this work
| | - Ulrike Baum
- These authors contributed equally to this work.,Impact Assessment Unit, Department of Public Health Solutions, National Institute for Health and Welfare, Helsinki, Finland
| | - Mia Brytting
- Unit for laboratory surveillance of viral pathogens and vaccine preventable diseases, Department of Microbiology, The Public Health Agency of Sweden, Solna, Sweden
| | - Niina Ikonen
- Viral Infections Unit, Department of Health Security, National Institute for Health and Welfare, Helsinki, Finland
| | - Anu Haveri
- Viral Infections Unit, Department of Health Security, National Institute for Health and Welfare, Helsinki, Finland
| | - Åsa Wiman
- Unit for laboratory surveillance of viral pathogens and vaccine preventable diseases, Department of Microbiology, The Public Health Agency of Sweden, Solna, Sweden
| | - Hanna Nohynek
- These authors contributed equally to this work.,Vaccination Programme Unit, Department of Health Security, National Institute for Health and Welfare, Helsinki, Finland
| | - Åke Örtqvist
- Department of Communicable Disease Control and Prevention, Stockholm County Council, and Karolinska Institutet, Department of Medicine Karolinska Solna, Unit of Infectious Diseases, Stockholm, Sweden.,These authors contributed equally to this work
| |
Collapse
|