Effects of PCV10 and PCV13 on pneumococcal serotype 6C disease, carriage, and antimicrobial resistance

BACKGROUND

The cross-protection of pneumococcal conjugate vaccines (PCV) against serotype 6C is not clearly documented, although 6C represents a substantial burden of pneumococcal disease in recent years. A systematic review by the World Health Organization that covered studies through 2016 concluded that available data were insufficient to determine if either PCV10 (which contains serotype 6B but not 6A) or PCV13 (containing serotype 6A and 6B) conferred protection against 6C.

METHODS

We performed a systematic review of randomized controlled trials and observational studies published between January 2010 - August 2022 (Medline/Embase), covering the direct, indirect, and overall effect of PCV10 and PCV13 against 6C invasive pneumococcal disease (IPD), non-IPD, nasopharyngeal carriage (NPC), and antimicrobial resistance (AMR).

RESULTS

Of 2548 publications identified, 112 were included. Direct vaccine effectiveness against 6C IPD in children ranged between 70 and 85 % for ≥ 1 dose PCV13 (n = 3 studies), was 94 % in fully PCV13 vaccinated children (n = 2), and -14 % for ≥ 1 dose of PCV10 (n = 1). Compared to PCV7, PCV13 efficacy against 6C NPC in children was 66 % (n = 1). Serotype 6C IPD rates or NPC prevalence declined post-PCV13 in most studies in children (n = 5/6) and almost half of studies in adults (n = 5/11), while it increased post-PCV10 for IPD and non-IPD in all studies (n = 6/6). Changes in AMR prevalence were inconsistent.

CONCLUSIONS

In contrast to PCV10, PCV13 vaccination consistently protected against 6C IPD and NPC in children, and provided some level of indirect protection to adults, supporting that serotype 6A but not 6B provides cross-protection to 6C. Vaccine policy makers and regulators should consider the effects of serotype 6A-containing PCVs against serotype 6C disease in their decisions.

Effectiveness of BNT162b2 BA.4/5 Bivalent mRNA Vaccine Against Symptomatic COVID-19 Among Immunocompetent Individuals Testing at a Large US Retail Pharmacy

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.

Effect of pneumococcal conjugate vaccines on viral respiratory infections: a systematic literature review

BACKGROUND

In addition to preventing pneumococcal disease, emerging evidence indicates that pneumococcal conjugate vaccines (PCVs) might indirectly reduce viral respiratory tract infections (RTI) by affecting pneumococcal-viral interactions.

METHODS

We performed a systematic review of interventional and observational studies published during 2000-2022 on vaccine efficacy/adjusted effectiveness (VE) and overall effect of PCV7, PCV9, PCV10, or PCV13 against viral RTI.

RESULTS

Sixteen of 1671 records identified were included. Thirteen publications described effects of PCVs against viral RTIs in children. VE against influenza ranged between 41-86% (n=4), except for the 2010-2011 influenza season. In a randomized controlled trial, PCV9 displayed efficacy against any viral RTI, human seasonal coronavirus, parainfluenza, and human metapneumovirus. Data in adults were limited (n=3). PCV13 VE ranged between 4-25% against viral lower RTI, 32-35% against COVID-19 outcomes, 24-51% against human seasonal coronavirus, and 13-36% against influenza A lower RTI, with some 95%CI spanning zero. No protection was found against adenovirus or rhinovirus in children or adults.

CONCLUSIONS

PCVs were associated with protection against some viral RTI, with the strongest evidence for influenza in children. Limited evidence for adults was generally consistent with pediatric data. Restricting public health evaluations to confirmed pneumococcal outcomes may underestimate the full impact of PCVs.

Surveillance of pneumococcal serotypes in adults hospitalised with acute lower respiratory tract infection in Bristol, UK

INTRODUCTION

Pneumococcus remains a major cause of adult lower respiratory tract infections (LRTI). Few data exist on the relative contribution of serotypes included in pneumococcal vaccines to community-acquired pneumonia (CAP) and non-pneumonic (NP) LRTI. We measured the burden of all and vaccine-serotype pneumococcal respiratory infection following SARS-CoV-2 emergence to inform evidence-based vaccination policy.

METHODS

A prospective cohort study at two Bristol hospitals (UK) including all adults age ≥ 18-years hospitalised with acute lower respiratory tract disease (aLRTD) from Nov2021-Nov2022. LRTI patients were classified as: a) radiographically-confirmed CAP (CAP+/RAD+), b) clinically-diagnosed CAP without radiological confirmation (CAP+/RAD-), or c) NP-LRTI. Pneumococcus was identified by blood culture, BinaxNOW™and serotype-specific urine antigen detection assays (UAD).

RESULTS

Of 12,083 aLRTD admissions, 10,026 had LRTI and 2,445 provided urine: 1,097 CAP + RAD+; 207 CAP + RAD-; and 1,141 NP-LRTI. Median age was 71.1y (IQR57.9-80.2) and Charlson comorbidity index = 4 (IQR2-5); 2.7 % of patients required intensive care, and 4.4 % died within 30-days of hospitalisation. Pneumococcus was detected in 280/2445 (11.5 %) participants. Among adults aged ≥ 65y and 18-64y, 12.9 % (198/1534) and 9.0 % (82/911), respectively, tested pneumococcus positive. We identified pneumococcus in 165/1097 (15.0 %) CAP + RAD+, 23/207 (11.1 %) CAP + RAD-, and 92/1141 (8.1 %) NP-LRTI cases. Of the 280 pneumococcal cases, 102 (36.4 %) were due to serotypes included in PCV13 + 6C, 115 (41.7 %) in PCV15 + 6C, 210 (75.0 %) in PCV20 + 6C/15C and 228 (81.4 %) in PPV23 + 15C. The most frequently identified serotypes were 8 (n = 78; 27.9 % of all pneumococcus), 7F (n = 25; 8.9 %), and 3 (n = 24; 8.6 %).

DISCUSSION

Among adults hospitalised with respiratory infection, pneumococcus is an important pathogen across all subgroups, including CAP+/RAD- and NP-LRTI. Despite 20-years of PPV23 use in adults ≥ 65-years and herd protection due to 17-years of PCV use in infants, vaccine-serotype pneumococcal disease still causes a significant proportion of LRTI adult hospitalizations. Direct adult vaccination with high-valency PCVs may reduce pneumococcal disease burden.

Multicountry Review of Streptococcus pneumoniae Serotype Distribution Among Adults With Community-Acquired Pneumonia

BACKGROUND

Nonbacteremic community-acquired pneumonia (CAP) is a leading presentation of severe pneumococcal disease in adults. Serotype-specific urinary antigen detection (UAD) assay can detect serotypes causing pneumococcal CAP, including nonbacteremic cases, and guide recommendations for use of higher valency pneumococcal conjugate vaccines (PCVs).

METHODS

Adult CAP serotype distribution studies that used both Pfizer UADs (UAD1, detects PCV13 serotypes; UAD2, detects PCV20 non-PCV13 serotypes plus 2, 9N, 17F, and 20) were identified by review of an internal study database and included if results were published. The percentages of all-cause radiologically confirmed CAP (RAD + CAP) due to individual or grouped (PCV13, PCV15, and PCV20) serotypes as detected from culture or UAD were reported.

RESULTS

Six studies (n = 2, United States; n = 1 each, Germany, Sweden, Spain, and Greece) were included. The percentage of RAD + CAP among adults ≥18 years with PCV13 serotypes equaled 4.6% to 12.9%, with PCV15 serotypes 5.9% to 14.5%, and with PCV20 serotypes 7.8% to 23.8%. The percentage of RAD + CAP due to PCV15 and PCV20 serotypes was 1.1-1.3 and 1.3-1.8 times higher than PCV13 serotypes, respectively.

CONCLUSIONS

PCV13 serotypes remain a cause of RAD + CAP among adults even in settings with pediatric PCV use. Higher valency PCVs among adults could address an important proportion of RAD + CAP in this population.

First evidence of tick-borne encephalitis (TBE) outside of Hokkaido Island in Japan

Tick-borne encephalitis (TBE) is an infection of the central nervous system caused by the tick-borne encephalitis virus (TBEV). TBE is endemic in parts of Europe and Asia. TBEV is transmitted to humans primarily by Ixodes ticks. There have been 5 TBE cases identified in Japan, all on the northern island of Hokkaido. Rodents with TBEV antibodies and Ixodes ticks have been identified throughout Japan, indicating that TBEV infection might be undiagnosed in Japan. Residual serum and cerebrospinal fluid (CSF) collected in 2010-2021 from 520 patients ≥1 year-of-age previously hospitalized with encephalitis or meningitis of unknown etiology at 15 hospitals (including 13 hospitals outside of Hokkaido) were screened by ELISA for TBEV IgG and IgM antibodies; TBEV infection was confirmed by the gold standard neutralization test. Residual serum was available from 331 (63.6%) patients and CSF from 430 (82.6%) patients; both serum and CSF were available from 189 (36.3%). Two patients were TBE cases: a female aged 61 years hospitalized for 104 days in Oita (2000 km south of Hokkaido) and a male aged 24 years hospitalized for 11 days in Tokyo (1200 km south of Hokkaido). Retrospective testing also identified a previous TBEV infection in a female aged 45 years hospitalized for 12 days in Okayama (1700 km south of Hokkaido). TBEV infection should be considered as a potential cause of encephalitis or meningitis in Japan. TBE cases are likely undiagnosed in Japan, including outside of Hokkaido, due to limited clinical awareness and lack of availability of TBE diagnostic tests.

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

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.

Immunogenicity and safety of a pentavalent meningococcal ABCWY vaccine in adolescents and young adults: an observer-blind, active-controlled, randomised trial

BACKGROUND

Meningococcal serogroups A, B, C, W, and Y cause nearly all meningococcal disease, and comprehensive protection requires vaccination against all five serogroups. We aimed to assess the immunogenicity and safety of a pentavalent MenABCWY vaccine comprising two licensed vaccines-meningococcal serogroup B-factor H binding protein vaccine (MenB-FHbp) and a quadrivalent meningococcal serogroup ACWY tetanus toxoid conjugate vaccine (MenACWY-TT)-compared with two doses of MenB-FHbp and a single dose of quadrivalent meningococcal serogroup ACWY CRM197-conjugate vaccine (MenACWY-CRM) as the active control. We previously reported the primary safety and immunogenicity data relating to the two-dose MenB-FHbp schedule. Here we report secondary outcomes and ad-hoc analyses relating to MenABCWY immunogenicity and safety.

METHODS

We did an observer-blind, active-controlled trial at 68 sites in the USA, Czech Republic, Finland, and Poland. Healthy individuals (aged 10-25 years) who had or had not previously received a MenACWY vaccine were randomly assigned (1:2) using an interactive voice or web-based response system, stratified by previous receipt of a MenACWY vaccine, to receive 0·5 mL of MenABCWY (months 0 and 6) and placebo (month 0) or MenB-FHbp (months 0 and 6) and MenACWY-CRM (month 0) via intramuscular injection into the upper deltoid. All individuals were masked to group allocation, except staff involved in vaccine dispensation, preparation, and administration; and protocol adherence. Endpoints for serogroups A, C, W, and Y included the proportion of participants who achieved at least a four-fold increase in serum bactericidal antibody using human complement (hSBA) titres between baseline and 1 month after each vaccination. For serogroup B, secondary endpoints included the proportion of participants who achieved at least a four-fold increase in hSBA titres from baseline for each of four primary test strains and the proportion of participants who achieved titres of at least the lower limit of quantitation against all four test strains combined at 1 month after the second dose. Endpoints for serogroups A, C, W, and Y were assessed in the modified intent-to-treat (mITT) population, which included all randomly assigned participants who received at least one vaccine dose and had at least one valid and determinate MenB or serogroup A, C, W, or Y assay result before vaccination up to 1 month after the second dose, assessed in ACWY-experienced and ACWY-naive participants separately. Secondary endpoints for serogroup B were analysed in the evaluable immunogenicity population, which included all participants in the mITT population who were randomly assigned to the group of interest, received all investigational products as randomly assigned, had blood drawn for assay testing within the required time frames, had at least one valid and determinate MenB assay result after the second vaccination, and had no important protocol deviations; outcomes were assessed in both ACWY-experienced and ACWY-naive populations combined. Non-inferiority of MenABCWY to MenACWY-CRM and MenB-FHbp was determined using a -10% non-inferiority margin for these endpoints. Reactogenicity and adverse events were assessed among all participants who received at least one vaccine dose and who had available safety data. This trial is registered with Clinicaltrials.gov, NCT03135834, and is complete.

FINDINGS

Between April 24 and November 10, 2017, 1610 participants (809 MenACWY-naive; 801 MenACWY-experienced) were randomly assigned: 544 to receive MenABCWY and placebo (n=272 MenACWY-naive; n=272 MenACWY-experienced) and 1066 to receive MenB-FHbp and MenACWY-CRM (n=537 MenACWY-naive; n=529 MenACWY-experienced). Among MenACWY-naive or MenACWY-experienced MenABCWY recipients, 75·5% (95% CI 69·8-80·6; 194 of 257; serogroup C) to 96·9% (94·1-98·7; 254 of 262; serogroup A) and 93·0% (88·4-96·2; 174 of 187; serogroup Y) to 97·4% (94·4-99·0; 224 of 230; serogroup W) achieved at least four-fold increases in hSBA titres against serogroups ACWY after dose 1 or 2, respectively, in ad-hoc analyses. Additionally, 75·8% (71·5-79·8; 320 of 422) to 94·7% (92·1-96·7; 396 of 418) of MenABCWY and 67·4% (64·1-70·6; 563 of 835) to 95·0% (93·3-96·4; 782 of 823) of MenB-FHbp recipients achieved at least four-fold increases in hSBA titres against MenB strains after dose 2 in secondary analyses; 79·9% (334 of 418; 75·7-83·6) and 74·3% (71·2-77·3; 605 of 814), respectively, achieved composite responses. MenABCWY was non-inferior to MenACWY-CRM (single dose) and to MenB-FHbp in ad-hoc analyses based on the proportion of participants with at least a four-fold increase in hSBA titres from baseline and (for MenB-FHbp only) composite responses. Reactogenicity events after vaccination were similarly frequent across groups, were mostly mild or moderate, and were unaffected by MenACWY experience. No adverse events causing withdrawals were related to the investigational product. Serious adverse events were reported in four (1·5%; 0·4-3·7) MenACWY-naive individuals in the MenABCWY group versus six (2·2%; 0·8-4·8) among MenACWY-experienced individuals in the MenABCWY group and 14 (1·3%; 0·7-2·2) in the active control group (MenACWY-experienced and MenACWY-naive individuals combined); none of these were considered related to the investigational product.

INTERPRETATION

MenABCWY immune responses were robust and non-inferior to MenACWY-CRM and MenB-FHbp administered separately, and MenABCWY was well tolerated. The favourable benefit-risk profile supports further MenABCWY evaluation as a simplified schedule compared with current adolescent meningococcal vaccination programmes.

FUNDING

Pfizer.

A systematic literature review of the effectiveness of tick-borne encephalitis vaccines in Europe

BACKGROUND

Tick-borne encephalitis (TBE) is an infectious disease caused by the tick-borne encephalitis virus (TBEV) in patients with symptoms of central nervous system (CNS) inflammation. More than 25 European countries have one or more TBE-endemic areas. Although two TBE vaccines, FSME-IMMUN® and Encepur®, are commonly used in Europe, there are no published reviews of the real-world effectiveness of TBE vaccines in Europe or elsewhere.

METHODS

We searched PubMed for TBE vaccine effectiveness (VE) articles and extracted information on country, study design, study period, study population, number of TBEV-infected cases, number of participants, and VE against TBEV infection and outcomes.

RESULTS

We identified 13 studies, conducted in Austria, the Czech Republic, Latvia, Germany, and Switzerland, published in 2003-2023. One study was a cohort investigation of a milk-borne outbreak. In the other studies, 11 (91.7%) used the screening method and two (16.7%) used a case-control design (one study used both). TBE vaccines were highly effective (VE estimates >92%) against TBEV infection in all age groups. Vaccines were also highly protective against mild infections (i.e., infections in patients without symptoms of CNS inflammation), and against infections resulting in TBE and hospitalization. Vaccines were also highly protective against the most serious outcomes such as hospitalization greater than 12 days. Product-specific VE estimates were also high, though limited data were available. Studies in Austria, the Czech Republic, Latvia, and Switzerland estimated that TBE vaccines prevented >1,000 TBE cases a year, avoiding many hospitalizations and deaths, in these countries combined.

CONCLUSIONS

Published VE studies demonstrate a high real-world effectiveness of the commercially available TBE vaccines in Europe. Although cases averted have been estimated in only four countries, TBE vaccination prevents thousands of cases in Europe each year. To prevent life-threatening TBE, TBE vaccine uptake and compliance with the vaccination schedule should be increased in residents of, and travelers to, TBE-endemic countries in Europe.

Estimated Effectiveness of Coadministration of the BNT162b2 BA.4/5 COVID-19 Vaccine With Influenza Vaccine

Importance

No data comparing the estimated effectiveness of coadministering COVID-19 vaccines with seasonal influenza vaccine (SIV) in the community setting exist.

Objective

To examine the comparative effectiveness associated with coadministering the BNT162b2 BA.4/5 bivalent mRNA COVID-19 vaccine (BNT162b2-biv [Pfizer BioNTech]) and SIV vs giving each vaccine alone.

Design, Setting, and Participants

A retrospective comparative effectiveness study evaluated US adults aged 18 years or older enrolled in commercial health insurance or Medicare Advantage plans and vaccinated with BNT162b2-biv only, SIV only, or both on the same day between August 31, 2022, and January 30, 2023. Individuals with monovalent or another brand of mRNA bivalent COVID-19 vaccine were excluded.

Exposure

Same-day coadministration of BNT162b2-biv and SIV; receipt of BNT162b2-biv only (for COVID-19-related outcomes) or SIV only (for influenza-related outcomes) were the comparator groups. For adults aged 65 years or older, only enhanced SIVs were included.

Main Outcomes and Measures

COVID-19-related and influenza-related hospitalization, emergency department (ED) or urgent care (UC) encounters, and outpatient visits.

Results

Overall, 3 442 996 individuals (57.0% female; mean [SD] age, 65 [16.7] years) were included. A total of 627 735 individuals had BNT162b2-biv and SIV vaccine coadministered, 369 423 had BNT162b2-biv alone, and 2 445 838 had SIV alone. Among those aged 65 years or older (n = 2 210 493; mean [SD] age, 75 [6.7] years; 57.9% female), the coadministration group had a similar incidence of COVID-19-related hospitalization (adjusted hazard ratio [AHR], 1.04; 95% CI, 0.87-1.24) and slightly higher incidence of emergency department or urgent care encounters (AHR, 1.12; 95% CI, 1.02-1.23) and outpatient visits (AHR, 1.06; 95% CI, 1.01-1.11) compared with the BNT162b2-biv-only group. Among individuals aged 18 to 64 years (n = 1 232 503; mean [SD] age, 47 [13.1] years; 55.4% female), the incidence of COVID-19-related outcomes was slightly higher among those who received both vaccines vs BNT162b2-biv alone (AHR point estimate range, 1.14-1.57); however, fewer events overall in this age group resulted in wider CIs. Overall, compared with those who received SIV alone, the coadministration group had a slightly lower incidence of most influenza-related end points (AHR point estimates 0.83-0.93 for those aged ≥65 years vs 0.76-1.08 for those aged 18-64 years). Negative control outcomes suggested residual bias and calibration of COVID-19-related and influenza-related outcomes with negative controls moved all estimates closer to the null, with most CIs crossing 1.00.

Conclusions and Relevance

In this study, coadministration of BNT162b2-biv and SIV was associated with generally similar effectiveness in the community setting against COVID-19-related and SIV-related outcomes compared with giving each vaccine alone and may help improve uptake of both vaccines.

Impact of SARS-CoV-2 infective exacerbation of chronic obstructive pulmonary disease on clinical outcomes in a prospective cohort study of hospitalised adults

OBJECTIVES

To determine whether acute exacerbations of chronic obstructive pulmonary disease (AECOPD) triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have worse outcomes than AECOPD caused by other infectious agents or non-infective AECOPD (NI-COPD).

DESIGN

A two-hospital prospective cohort study of adults hospitalised with acute respiratory disease. We compared outcomes with AECOPD and a positive test for SARS-CoV-2 (n = 816), AECOPD triggered by other infections (n = 3038) and NI-COPD (n = 994). We used multivariable modelling to adjust for potential confounders and assessed variation by seasons associated with different SARS-CoV-2 variants.

SETTING

Bristol UK, August 2020-May 2022.

PARTICIPANTS

Adults (≥18 y) hospitalised with AECOPD.

MAIN OUTCOME MEASURES

We determined the risk of positive pressure support, longer hospital admission and mortality following hospitalisation with AECOPD due to non-SARS-CoV-2 infection compared with SARS-CoV-2 AECOPD and NI-COPD.

RESULTS

Patients with SARS-CoV-2 AECOPD, in comparison to non-SARS-CoV-2 infective AECOPD or NI-COPD, more frequently required positive pressure support (18.5% and 7.5% vs. 11.7%, respectively), longer hospital stays (median [interquartile range, IQR]: 7 [3-15] and 5 [2-10] vs. 4 [2-9] days, respectively) and had higher 30-day mortality (16.9% and 11.1% vs. 5.9%, respectively) (all p < 0.001). In adjusted analyses, SARS-CoV-2 AECOPD was associated with a 55% (95% confidence interval [95% CI]: 24-93), 26% (95% CI: 15-37) and 35% (95% CI: 10-65) increase in the risk of positive pressure support, hospitalisation length and 30-day mortality, respectively, relative to non-SARS-CoV-2 infective AECOPD. The difference in risk remained similar during periods of wild-type, Alpha and Delta SARS-CoV-2 strain dominance, but diminished during Omicron dominance.

CONCLUSIONS

SARS-CoV-2-related AECOPD had worse patient outcomes compared with non-SARS-CoV-2 AECOPD or NI-AECOPD, although the difference in risks was less pronounced during Omicron dominance.

Estimated Incidence of Symptomatic Lyme Borreliosis Cases in Lublin, Poland in 2021

Lyme borreliosis (LB), the most common tick-borne disease in Europe, is endemic to Poland. Despite public health surveillance with mandatory reporting of LB cases by physicians and laboratories, many symptomatic LB cases are not included in surveillance in Poland. We estimated the extent of the under-ascertainment of symptomatic LB cases via surveillance in the Polish province of Lublin to better understand Poland's LB burden. The number of incident symptomatic LB cases in Lublin in 2010 was estimated from two seroprevalence studies conducted among adults in Lublin, as well as estimates of the proportion of asymptomatic LB cases and the duration of LB antibody persistence. The estimated number of incident symptomatic LB cases was compared to the number of surveillance-reported cases in Lublin to derive an under-ascertainment multiplier. This multiplier was applied to the number of surveillance-reported cases in 2021 to estimate the number and population-based incidence of symptomatic LB cases in Lublin in 2021. We estimate that there are 5.9 symptomatic LB cases for every surveillance-reported LB case in Lublin. Adjusting for under-ascertainment, the estimated number of symptomatic LB cases in Lublin in 2021 was 6204 (population-based incidence: 467.6/100,000). After adjustment for under-ascertainment, the incidence of symptomatic LB in Lublin, Poland, is high.

Receipt of BNT162b2 Vaccine and COVID-19 Ambulatory Visits in US Children Younger Than 5 Years

This study examines the association of the receipt of wild-type BNT162b2 vaccine with medically attended COVID-19 outcomes among children younger than 5 years in the US.

Effectiveness of Tick-borne Encephalitis Vaccines in Children, Latvia, 2018-2020

BACKGROUND

Tick-borne encephalitis (TBE) is an infection by the tick-borne encephalitis virus (TBEV) with symptoms of central nervous system inflammation. TBE is endemic in Latvia and other parts of Europe. TBE vaccination is recommended for children in Latvia. TBE vaccine effectiveness (VE) was estimated in Latvia, a country with high TBE incidence, providing the first VE estimates against a range of TBEV infection outcomes in children 1-15 years-of-age.

METHODS

Rīga Stradinš University conducted nationwide surveillance for suspected TBE cases. Serum and cerebrospinal fluid were ELISA tested for TBEV-specific IgG and IgM antibodies. A fully vaccinated child was an individual who had received the 3-dose primary series and appropriately timed boosters. The proportion of laboratory-confirmed TBE cases fully vaccinated (PCV) was determined from interviews and medical records. The proportion of the general population fully vaccinated (PPV) was determined from national surveys conducted in 2019 and 2020. TBE VE in children 1-15 years-of-age was estimated using the screening method: VE = 1 - [PCV/(1 - PCV)/PPV/(1 - PPV)].

RESULTS

From 2018 to 2020, surveillance identified 36 TBE cases in children 1-15 years-of-age; all were hospitalized, 5 (13.9%) for >12 days. Of the TBE cases, 94.4% (34/36) were unvaccinated compared with 43.8% of children in the general population. VE against TBE hospitalization in children 1-15 years-of-age was 94.9% (95% confidence interval 63.1-99.3). In 2018-2020, vaccination in children 1-15 years-of-age averted 39 hospitalized TBE cases.

CONCLUSION

Pediatric TBE vaccines were highly effective in preventing TBE in children. Increasing TBE vaccine uptake in children is essential to maximize the public health impact of TBE vaccination.

Validation of Claims-Based Algorithm for Lyme Disease, Massachusetts, USA

Compared with notifiable disease surveillance, claims-based algorithms estimate higher Lyme disease incidence, but their accuracy is unknown. We applied a previously developed Lyme disease algorithm (diagnosis code plus antimicrobial drug prescription dispensing within 30 days) to an administrative claims database in Massachusetts, USA, to identify a Lyme disease cohort during July 2000-June 2019. Clinicians reviewed and adjudicated medical charts from a cohort subset by using national surveillance case definitions. We calculated positive predictive values (PPVs). We identified 12,229 Lyme disease episodes in the claims database and reviewed and adjudicated 128 medical charts. The algorithm's PPV for confirmed, probable, or suspected cases was 93.8% (95% CI 88.1%-97.3%); the PPV was 66.4% (95% CI 57.5%-74.5%) for confirmed and probable cases only. In a high incidence setting, a claims-based algorithm identified cases with a high PPV, suggesting it can be used to assess Lyme disease burden and supplement traditional surveillance data.

Distribution of serotypes causing invasive pneumococcal disease in older adults from high-income countries and impact of pediatric and adult vaccination policies

BACKGROUND

Neither indirect protection through use of 13-valent and 10-valent pneumococcal conjugate vaccines (PCV13 and PCV10) in pediatric National Immunization Programs (NIPs) nor direct vaccination with the 23-valent polysaccharide vaccine have eliminated vaccine serotype invasive pneumococcal disease (IPD) in older adults. Vaccinating older adults with higher-valency PCV15 and PCV20 could address remaining IPD due to pediatric PCV serotypes plus additional IPD due to serotypes included in these vaccines.

METHODS

We collected serotype-specific IPD data in older adults (≥65 years in most countries), from national or regional surveillance systems or hospital networks of 33 high-income countries. Data were from official government websites, online databases, surveillance system reports, published literature, and personal communication with in-country investigators. Average percentages of IPD serotypes were calculated.

RESULTS

Among 52,905 cases of IPD with a serotype identified, PCV13 serotypes accounted for 33.7% of IPD (55.8% and 30.6% for countries with PCV10 and PCV13 in the pediatric NIP), most commonly serotypes 3 (14.9%) and 19A (7.0%). PCV15 and PCV20 would cover an additional 10.4% and 32.9% of older adult IPD beyond PCV13 serotypes (PCV10 countries: 7.7% and 23.3%; PCV13 countries: 10.6% and 34.6%). The most common of these additional serotypes were 8 (9.9%), 22F (7.9%), 12F (4.6%), and 11A (3.3%). PPSV23 policies for older adults were not correlated with lower IPD percentages due to PPSV23 serotypes.

CONCLUSIONS

Vaccinating older adults with higher-valency PCVs, especially PCV20, could substantially reduce the remaining IPD burden in high-income countries, regardless of current PCV use in pediatric NIPs and adult PPSV23 policies.

Real-world impact and effectiveness of MenACWY-TT

In response to escalating cases of serogroup W (MenW) invasive meningococcal disease (IMD), multiple countries introduced quadrivalent conjugate MenACWY vaccines into their national immunization programs (NIPs). Here, we summarize the real-world impact and vaccine effectiveness (VE) data of MenACWY-TT from Chile, England, the Netherlands, and Australia. Incidence rate reductions (IRRs) and VE from baseline to post-NIP period were extracted from publications or calculated. After the administration of a single dose of MenACWY-TT, substantial IRRs of MenCWY were observed across the countries in vaccine-eligible age groups (83%-85%) and via indirect protection in non-vaccine-eligible age groups (45%-53%). The impact of MenACWY-TT was primarily driven by MenW IRRs, as seen in vaccine-eligible age groups (65%-92%) and non-vaccine-eligible age groups (41%-57%). VE against MenW was reported in vaccine-eligible toddlers (92%) in the Netherlands and in vaccine-eligible adolescents/young adults (94%) in England. These real-world data support the implementation and continued use of MenACWY-TT in NIPs.

Safety and immunogenicity of a multivalent pneumococcal conjugate vaccine given with 13-valent pneumococcal conjugate vaccine in healthy infants: A phase 2 randomized trial

Use of pneumococcal conjugate vaccines (PCVs) has led to substantial reductions in the global burden of pediatric pneumococcal disease. Expansion of serotype coverage has been achieved by increasing PCV valency, but this may carry the potential risk of antibody interference. A complementary 7-valent PCV (cPCV7) including polysaccharide conjugates from 7 non-13-valent (PCV13) serotypes was developed to potentially complement PCV13-mediated protection and expand serotype coverage. This study evaluated cPCV7 and PCV13 coadministered in separate limbs or separated in time in infants. This phase 2, multicenter, open-label study included 512 infants randomized 1:1:1 to receive cPCV7 coadministered with PCV13 at ages 2, 4, 6, and 12 months (cPCV7 Coadministered); cPCV7 given at ages 3, 5, 7, and 13 months, 3‒5 weeks after PCV13 (cPCV7 Separated); or PCV13 at ages 2, 4, 6, and 12 months followed by a single supplemental dose of cPCV7 at 13 months (PCV13 Control). Safety evaluations included local reactions, systemic events, and adverse events. Serotype-specific immunoglobulin G concentrations and opsonophagocytic activity titers were assessed. The safety profile of cPCV7 was similar to that of PCV13. cPCV7 was well-tolerated in infants when coadministered with or given separately from PCV13. Robust and functional immune responses for all cPCV7 serotypes were observed in both cPCV7 groups. No immunologic interference was observed for either the cPCV7 or PCV13 serotypes with coadministration. A single cPCV7 dose induced immune responses in toddlers. These findings support potential coadministration of a complementary PCV to supplement protection provided by existing PCVs.Trial registration: ClinicalTrials.gov, NCT03550313.

Effectiveness of tick-borne encephalitis vaccination in Latvia, 2018-2020: an observational study

OBJECTIVES

Tick-borne encephalitis (TBE) is an infection by the tick-borne encephalitis virus (TBEV) that results in symptoms of central nervous system inflammation. TBE is endemic in Latvia and other European countries. TBE vaccines are commonly used in Latvia, but vaccine effectiveness estimates are limited.

METHODS

Study staff at Rīga Stradinš University conducted nationwide active surveillance for TBEV infections. Serum and cerebrospinal fluid were ELISA-tested for TBEV-specific IgG and IgM antibodies. Vaccination history was collected by interview and medical record review. Utilising data from surveillance and population surveys, vaccine effectiveness (with 95% confidence intervals) and cases averted were estimated using the screening method.

RESULTS

There were 587 laboratory-identified TBE cases from 2018-2020; 98.1% (576/587) were unvaccinated, 1.5% (9/587) were unknown or partially-vaccinated, and 0.3% (2/587) were fully-vaccinated (three-dose primary series and appropriately timed boosters). TBE resulted in the death of 1.7% (10/587) of TBE cases. TBE vaccine history was ascertained from 92.0% (13,247/14,399) people from the general population: 38.6% (5113/13,247) were unvaccinated, 26.3% (3484/13,247) were fully-vaccinated, and 35.1% (4650/13,247) were partially-vaccinated. TBE vaccine effectiveness was 99.5% (98.0-99.9) against TBE, 99.5% (97.9-99.9) against TBE hospitalisation, 99.3% (94.8-99.9) against moderate/severe TBE, and 99.2% (94.4-99.9) against TBE hospitalisation >12 days. From 2018-2020, vaccination averted 906 TBE cases, including 20 deaths.

CONCLUSIONS

TBE vaccine was highly effective in preventing TBE, moderate and severe disease, and prolonged hospitalisation. To prevent life-threatening TBE, TBE vaccine uptake and compliance should be increased in Latvia and other European regions where TBE is endemic.

Diagnosis of Respiratory Syncytial Virus in Adults Substantially Increases When Adding Sputum, Saliva, and Serology Testing to Nasopharyngeal Swab RT-PCR

INTRODUCTION

Nearly all existing respiratory syncytial virus (RSV) incidence estimates are based on real-time polymerase chain reaction (RT-PCR) testing of nasal or nasopharyngeal (NP) swabs. Adding testing of additional specimen types to NP swab RT-PCR increases RSV detection. However, prior studies only made pairwise comparisons and the synergistic effect of adding multiple specimen types has not been quantified. We compared RSV diagnosis by NP swab RT-PCR alone versus NP swab plus saliva, sputum, and serology.

METHODS

This was a prospective cohort study over two study periods (27 December 2021 to 1 April 2022 and 22 August 2022 to 11 November 2022) of patients aged ≥ 40 years hospitalized for acute respiratory illness (ARI) in Louisville, KY. NP swab, saliva, and sputum specimens were collected at enrollment and PCR tested (Luminex ARIES platform). Serology specimens were obtained at acute and convalescent timepoints (enrollment and 30-60-day visit). RSV detection rate was calculated for NP swab alone and for NP swab plus all other specimen type/test.

RESULTS

Among 1766 patients enrolled, 100% had NP swab, 99% saliva, 34% sputum, and 21% paired serology specimens. RSV was diagnosed in 56 (3.2%) patients by NP swab alone, and in 109 (6.2%) patients by NP swab plus additional specimens, corresponding to a 1.95 times higher rate [95% confidence interval (CI) 1.62, 2.34]. Limiting the comparison to the 150 subjects with all four specimen types available (i.e., NP swab, saliva, sputum, and serology), there was a 2.60-fold increase (95% CI 1.31, 5.17) compared to NP swab alone (3.3% versus 8.7%). Sensitivities by specimen type were: NP swab 51%, saliva 70%, sputum 72%, and serology 79%.

CONCLUSIONS

Diagnosis of RSV in adults was several-fold greater when additional specimen types were added to NP swab, even with a relatively low percentage of subjects with sputum and serology results available. Hospitalized RSV ARI burden estimates in adults based solely on NP swab RT-PCR should be adjusted for underestimation.

Misdiagnosis of Clostridioides difficile Infections by Standard-of-Care Specimen Collection and Testing among Hospitalized Adults, Louisville, Kentucky, USA, 2019-20201

Although Clostridioides difficile infection (CDI) incidence is high in the United States, standard-of-care (SOC) stool collection and testing practices might result in incidence overestimation or underestimation. We conducted diarrhea surveillance among inpatients >50 years of age in Louisville, Kentucky, USA, during October 14, 2019-October 13, 2020; concurrent SOC stool collection and CDI testing occurred independently. A study CDI case was nucleic acid amplification test‒/cytotoxicity neutralization assay‒positive or nucleic acid amplification test‒positive stool in a patient with pseudomembranous colitis. Study incidence was adjusted for hospitalization share and specimen collection rate and, in a sensitivity analysis, for diarrhea cases without study testing. SOC hospitalized CDI incidence was 121/100,000 population/year; study incidence was 154/100,000 population/year and, in sensitivity analysis, 202/100,000 population/year. Of 75 SOC CDI cases, 12 (16.0%) were not study diagnosed; of 109 study CDI cases, 44 (40.4%) were not SOC diagnosed. CDI incidence estimates based on SOC CDI testing are probably underestimated.

Estimated number of symptomatic Lyme borreliosis cases in Germany in 2021 after adjusting for under-ascertainment

BACKGROUND

Although nine of 16 federal states in Germany conduct public health surveillance for Lyme borreliosis (LB), the extent of under-ascertainment is unknown.

OBJECTIVE

As a model for European countries that conduct LB surveillance, we sought to estimate the population-based incidence of symptomatic LB after adjusting for under-ascertainment.

METHODS

Estimating seroprevalence-derived under-ascertainment relies on data from seroprevalence studies, public health surveillance, and published literature. The number of symptomatic LB cases in states that conduct LB surveillance was estimated from studies reporting the seroprevalence of antibodies against Borrelia burgdorferi sensu lato, the proportion of LB cases that are asymptomatic, and the duration of antibody detection. The number of estimated incident symptomatic LB cases was compared with the number of surveillance-reported LB cases to derive under-ascertainment multipliers. The multipliers were applied to the number of 2021 surveillance-reported LB cases to estimate the population-based incidence of symptomatic LB in Germany.

RESULTS

Adjusting for seroprevalence-based under-ascertainment multipliers, the estimated number of symptomatic LB cases in states that conducted surveillance was 129,870 (408 per 100,000 population) in 2021. As there were 11,051 surveillance-reported cases in 2021 in these states, these data indicate there were 12 symptomatic LB cases for every surveillance-reported LB case.

CONCLUSIONS

We demonstrate that symptomatic LB is underdetected in Germany and that this seroprevalence-based approach can be applied elsewhere in Europe where requisite data are available. Nationwide expansion of LB surveillance would further elucidate the true LB disease burden in Germany and could support targeted disease prevention efforts to address the high LB disease burden.

Estimated Number of Symptomatic Lyme Borreliosis Cases in Adults in Finland in 2021 Using Seroprevalence Data to Adjust the Number of Surveillance-Reported Cases: A General Framework for Accounting for Underascertainment by Public Health Surveillance

Background: Finland conducts public health surveillance for Lyme borreliosis (LB) based on clinically diagnosed and laboratory-confirmed cases. We used data from seroprevalence studies to determine the extent to which LB cases were underascertained by public health surveillance. Methods: The numbers of incident symptomatic LB cases in 2011 in six regions in Finland were estimated using (1) data from Borrelia burgdorferi sensu lato seroprevalence studies, (2) estimates of the proportion of LB infections that are asymptomatic, and (3) estimates of the duration of LB antibody detection. The numbers of estimated incident symptomatic LB cases were compared with the numbers of surveillance-reported LB cases to estimate regional underascertainment multipliers. Underascertainment multipliers were applied to the numbers of surveillance-reported LB cases in each region in 2021 and summed to estimate the number of symptomatic LB cases in Finland among adults in 2021. A sensitivity analysis evaluated the impact of different durations of antibody detection. Results: Using an asymptomatic proportion of 50% and a 10-year duration of antibody detection, the estimated regional underascertainment multipliers in Finland ranged from 1.0 to 12.2. Applying the regional underascertainment multipliers to surveillance-reported LB cases in each region and summing nationally, there were 19,653 symptomatic LB cases in Finland among adults in 2021 (526/100,000 per year). With 7,346 surveillance-reported LB cases in Finland among adults in 2021, the estimated number of symptomatic LB cases indicate that there were 2.7 symptomatic LB cases for every surveillance-reported LB case among adults. With a 5- or 20-year duration of antibody detection, there were an estimated 36,824 or 11,609 symptomatic LB cases among adults in 2021, respectively. Discussion: Finland has robust public health surveillance for LB, but cases are underascertained. This framework for estimating LB underascertainment can be used in other countries that conduct LB surveillance and have conducted representative LB seroprevalence studies.

Incidence of Lyme Borreliosis in Europe from National Surveillance Systems (2005-2020)

Background: Lyme borreliosis (LB) is the most common tick-borne disease in Europe. To inform European intervention strategies, including vaccines under development, we conducted a systematic review for LB incidence. Methods: We searched publicly available surveillance data reporting LB incidence in Europe from 2005 to 2020. Population-based incidence was calculated as the number of reported LB cases per 100,000 population per year (PPY), and high LB risk areas (incidence >10/100,00 PPY for 3 consecutive years) were estimated. Results: Estimates of LB incidence were available for 25 countries. There was marked heterogeneity in surveillance systems (passive vs. mandatory and sentinel sites vs. national), case definitions (clinical, laboratory, or both), and testing methods, limiting comparison across countries. Twenty-one countries (84%) had passive surveillance; four (Belgium, France, Germany, and Switzerland) used sentinel surveillance systems. Only four countries (Bulgaria, France, Poland, and Romania) used standardized case definitions recommended by European public health institutions. Among all surveillance systems and considering any case definition for the most recently available years, national LB incidences were highest in Estonia, Lithuania, Slovenia, and Switzerland (>100 cases/100,000 PPY), followed by France and Poland (40-80/100,000 PPY), and Finland and Latvia (20-40/100,000 PPY). Incidences were lowest in Belgium, Bulgaria, Croatia, England, Hungary, Ireland, Norway, Portugal, Romania, Russia, Scotland, and Serbia (<20/100,000 PPY). At the subnational level, highest LB incidences (>100/100,000 PPY) were observed in areas of Belgium, Czech Republic, France, Germany, and Poland. Overall, on average 128,888 cases are reported annually. An estimated 202/844 million (24%) persons in Europe reside in areas of high LB incidence and 202/469 million (43.2%) persons reside in areas of high LB incidence among countries with surveillance data. Conclusion: Our review showed substantial variability in reported LB incidence across and within European countries, with highest incidences reported from the Eastern, Northern (Baltic states and Nordic countries), and Western Europe surveillance systems. Standardization of surveillance systems, including wider implementation of common case definitions, is urgently needed to interpret the range of differences in LB incidence observed across European countries.

Effectiveness of nirmatrelvir-ritonavir in preventing hospital admissions and deaths in people with COVID-19: a cohort study in a large US health-care system

BACKGROUND

In the USA, oral nirmatrelvir-ritonavir is authorised for use in patients aged 12 years or older with mild-to-moderate COVID-19 who are at risk of progression to severe disease and hospitalisation. We aimed to establish the effectiveness of nirmatrelvir-ritonavir in preventing hospital admissions and death in people with COVID-19 in an outpatient prescribing context in the USA.

METHODS

In this matched observational outpatient cohort study in the Kaiser Permanente Southern California (CA, USA) health-care system, data were extracted from electronic health records of non-hospitalised patients aged 12 years or older who received a positive SARS-CoV-2 PCR test result (their index test) between April 8 and Oct 7, 2022, and had not received another positive test result within the preceding 90 days. We compared outcomes between people who received nirmatrelvir-ritonavir and those who did not receive nirmatrelvir-ritonavir by matching cases by date, age, sex, clinical status (including care received, the presence or absence of acute COVID-19 symptoms at testing, and time from symptom onset to testing), vaccination history, comorbidities, health-care seeking during the previous year, and BMI. Our primary endpoint was the estimated effectiveness of nirmatrelvir-ritonavir in preventing hospital admissions or death within 30 days of a positive test for SARS-CoV-2.

FINDINGS

7274 nirmatrelvir-ritonavir recipients and 126 152 non-recipients with positive SARS-CoV-2 tests were included in our study. 5472 (75·2%) treatment recipients and 84 657 (67·1%) non-recipients were tested within 5 days of symptom onset. Nirmatrelvir-ritonavir had an overall estimated effectiveness of 53·6% (95% CI 6·6-77·0) in preventing hospital admission or death within 30 days of a positive test for SARS-CoV-2, which increased to 79·6% (33·9-93·8) when nirmatrelvir-ritonavir was dispensed within 5 days of symptom onset. Within the subgroup of patients tested within 5 days of symptom onset and whose treatment was dispensed on the day of their test, the estimated effectiveness of nirmatrelvir-ritonavir was 89·6% (50·2-97·8).

INTERPRETATION

In a setting with high levels of COVID-19 vaccine uptake, nirmatrelvir-ritonavir effectively reduced the risk of hospital admission or death within 30 days of a positive outpatient SARS-CoV-2 test.

FUNDING

US Centers for Disease Control and Prevention and US National Institutes of Health.

Effectiveness and durability of BNT162b2 vaccine against hospital and emergency department admissions due to SARS-CoV-2 omicron sub-lineages BA.1 and BA.2 in a large health system in the USA: a test-negative, case-control study

BACKGROUND

The SARS-CoV-2 omicron (B.1.1.529 BA.1) lineage was first detected in November, 2021, and is associated with reduced vaccine effectiveness. By March, 2022, BA.1 had been replaced by sub-lineage BA.2 in the USA. As new variants evolve, vaccine performance must be continually assessed. We aimed to evaluate the effectiveness and durability of BNT162b2 (Pfizer-BioNTech) against hospital and emergency department admissions for BA.1 and BA.2.

METHODS

In this test-negative, case-control study, we sourced data from the electronic health records of adult (aged ≥18 years) members of Kaiser Permanente Southern California (KPSC), which is a health-care system in the USA, who were admitted to one of 15 KPSC hospitals or emergency departments (without subsequent hospitalisation) between Dec 27, 2021, and June 4, 2022, with an acute respiratory infection and were tested for SARS-CoV-2 by RT-PCR. Omicron sub-lineage was determined by use of sequencing, spike gene target failure, and the predominance of variants in certain time periods. Our main outcome was the effectiveness of two or three doses of BNT162b2 in preventing emergency department or hospital admission. Variant-specific vaccine effectiveness was evaluated by comparing the odds ratios from logistic regression models of vaccination between test-positive cases and test-negative controls, adjusting for the month of admission, age, sex, race and ethnicity, body-mass index, Charlson Comorbidity Index, previous influenza or pneumococcal vaccines, and previous SARS-CoV-2 infection. We also assessed effectiveness by the time since vaccination. This study is registered at ClinicalTrials.gov, NCT04848584, and is ongoing.

FINDINGS

Of 65 813 total admissions during the study period, we included 16 994 in our analyses, of which 7435 were due to BA.1, 1056 were due to BA.2, and 8503 were not due to SARS-CoV-2. In adjusted analyses, two-dose vaccine effectiveness was 40% (95% CI 27 to 50) for hospitalisation and 29% (18 to 38) for emergency department admission against BA.1 and 56% (31 to 72) for hospitalisation and 16% (-5 to 33) for emergency department admission against BA.2. Three-dose vaccine effectiveness was 79% (74 to 83) for hospitalisation and 72% (67 to 77) for emergency department admission against BA.1 and 71% (55 to 81) for hospitalisation and 21% (1 to 37) for emergency department admission against BA.2. Less than 3 months after the third dose, vaccine effectiveness was 80% (74 to 84) for hospitalisation and 74% (69 to 78) for emergency department admission against BA.1. Vaccine effectiveness 3 months or more after the third dose was 76% (69 to 82) against BA.1-related hospitalisation and 65% (56 to 73) against BA.1-related emergency department admission. Against BA.2, vaccine effectiveness was 74% (47 to 87) for hospitalisation and 59% (40 to 72) for emergency department admission at less than 3 months after the third dose and 70% (53 to 81) for hospitalisation and 5% (-21 to 25) for emergency department admission at 3 months or more after the third dose.

INTERPRETATION

Two doses of BNT162b2 provided only partial protection against BA.1-related and BA.2-related hospital and emergency department admission, which underscores the need for booster doses against omicron. Although three doses offered high levels of protection (≥70%) against hospitalisation, variant-adapted vaccines are probably needed to improve protection against less severe endpoints, like emergency department admission, especially for BA.2.

FUNDING

Pfizer.

Severity of Omicron (B.1.1.529) and Delta (B.1.617.2) SARS-CoV-2 infection among hospitalised adults: A prospective cohort study in Bristol, United Kingdom

Background

There is an urgent public health need to evaluate disease severity in adults hospitalised with Delta and Omicron SARS-CoV-2 variant infections. However, limited data exist assessing severity of disease in adults hospitalised with Omicron SARS-CoV-2 infections, and to what extent patient-factors, including vaccination, age, frailty and pre-existing disease, affect variant-dependent disease severity.

Methods

A prospective cohort study of adults (≥18 years of age) hospitalised with acute lower respiratory tract disease at acute care hospitals in Bristol, UK conducted over 10-months. Delta or Omicron SARS-CoV-2 infection was defined by positive SARS-CoV-2 PCR and variant identification or inferred by dominant circulating variant. We constructed adjusted regression analyses to assess disease severity using three different measures: FiO₂ >28% (fraction inspired oxygen), World Health Organization (WHO) outcome score >5 (assessing need for ventilatory support), and hospital length of stay (LOS) >3 days following admission for Omicron or Delta infection.

Findings

Independent of other variables, including vaccination, Omicron variant infection in hospitalised adults was associated with lower severity than Delta. Risk reductions were 58%, 67%, and 16% for supplementary oxygen with >28% FiO₂ [Relative Risk (RR) = 0.42 (95%CI: 0.34-0.52), P < 0.001], WHO outcome score >5 [RR = 0.33 (95%CI: 0.21-0.50), P < 0.001], and to have had a LOS > 3 days [RR = 0.84 (95%CI: 0.76-0.92), P < 0.001]. Younger age and vaccination with two or three doses were also independently associated with lower COVID-19 severity.

Interpretation

We provide reassuring evidence that Omicron infection results in less serious adverse outcomes than Delta in hospitalised patients. Despite lower severity relative to Delta, Omicron infection still resulted in substantial patient and public health burden and an increased admission rate of older patients with Omicron which counteracts some of the benefit arising from less severe disease.

Funding

AvonCAP is an investigator-led project funded under a collaborative agreement by Pfizer.

BNT162b2 against COVID-19-associated Emergency Department and Urgent Care Visits among Children 5-11 Years of Age: a Test Negative Design

In a 1:1 matched test-negative design among 5-11-year-olds in the Kaiser Permanente Southern California health system (n=3984), BNT162b2 effectiveness against omicron-related emergency department or urgent care encounters was 60% [95%CI: 47-69] <3 months post-dose-two and 28% [8-43] after ≥3 months. A booster improved protection to 77% [53-88].

Effectiveness of nirmatrelvir-ritonavir against hospital admission or death: a cohort study in a large US healthcare system

BACKGROUND

In the United States, oral nirmatrelvir-ritonavir (PaxlovidTM) is authorized for use among patients aged 12+ years with mild-to-moderate SARS-CoV-2 infection who are at risk for progression to severe COVID-19, including hospitalization. However, effectiveness under current real-world prescribing practices in outpatient settings is unclear.

METHODS

We undertook a matched observational cohort study of non-hospitalized cases with SARS-CoV-2 infection to compare outcomes among those who received or did not receive nirmatrelvir-ritonavir within the Kaiser Permanente Southern California healthcare system. Cases were matched on testing date, age, sex, clinical status (including care received, presence or absence of acute COVID-19 symptoms at testing, and time from symptom onset to testing), history of vaccination, Charlson comorbidity index, prior-year healthcare utilization, and body mass index. Primary analyses evaluated effectiveness of nirmatrelvir-ritonavir in preventing hospital admission or death within 30 days after a positive test. Secondary analyses evaluated effectiveness against intensive care unit admission, mechanical ventilation, or death within 60 days after a positive test. We measured treatment effectiveness as (1-adjusted hazards ratio [aHR])*100%, estimating the aHR via Cox proportional hazards models.

RESULTS

Analyses included 7,274 nirmatrelvir-ritonavir recipients and 126,152 non-recipients with positive results from SARS-CoV-2 tests undertaken in outpatient settings between 8 April and 7 October, 2022. Overall, 114,208 (85.6%) and 81,739 (61.3%) of 133,426 participants had received 2+ and 3+ COVID-19 vaccine doses, respectively. A total of 111,489 (83.6% of 133,426) cases were symptomatic at the point of testing, with 5,472 (75.2% of 7,274) treatment recipients and 84,657 (67.1% of 126,152) non-recipients testing within 0-5 days after symptom onset. Effectiveness in preventing hospital admission or death within 30 days after a positive test was 79.6% (95% confidence interval: 33.9% to 93.8%) for cases dispensed nirmatrelvir-ritonavir within 0-5 days after symptom onset; within the subgroup of cases tested 0-5 days after symptom onset and dispensed treatment on the day of their test, effectiveness was 89.6% (50.2% to 97.8%). Effectiveness declined to 43.8% (-33.3% to 81.7%) for treatment course dispensed 6+ days after symptom onset or to cases who were not experiencing acute clinical symptoms. Overall, for cases dispensed treatment at any time within their clinical course, effectiveness was 53.6% (6.6% to 77.0%). Effectiveness in preventing the secondary endpoint of intensive care unit admission, mechanical ventilation, or death within 60 days after a positive test was 89.2% (-25.0% to 99.3%) for cases dispensed treatment 0-5 days after symptom onset and 84.1% (18.8% to 96.9%) for cases dispensed treatment at any time. Subgroup analyses identified similar effectiveness estimates among cases who had received 2+ or 3+ COVID-19 vaccine doses.

IMPLICATIONS

In a setting with high levels of COVID-19 vaccine and booster uptake, receipt of nirmatrelvir-ritonavir 0-5 days after symptom onset was associated with substantial reductions in risk of hospital admission or death within 30 days after a positive outpatient SARS-CoV-2 test.

Analysis of mRNA COVID-19 Vaccine Uptake Among Immunocompromised Individuals in a Large US Health System

Importance

Immunocompromised individuals are at increased risk for severe outcomes due to SARS-CoV-2 infection. Given the varying and complex nature of COVID-19 vaccination recommendations, it is important to understand COVID-19 vaccine uptake in this vulnerable population.

Objective

To assess mRNA COVID-19 vaccine uptake and factors associated with uptake among immunocompromised individuals from December 14, 2020, through August 6, 2022.

Design, Setting, and Participants

This cohort study was conducted with patients of Kaiser Permanente Southern California (KPSC), an integrated health care system in the US. The study included patients aged 18 years or older who were immunocompromised (individuals with an immunocompromising condition or patients who received immunosuppressive medications in the year prior to December 14, 2020) and still met criteria for being immunocompromised 1 year later.

Exposures

Age, sex, self-identified race and ethnicity, prior positive COVID-19 test result, immunocompromising condition, immunomodulating medication, comorbidities, health care utilization, and neighborhood median income.

Main Outcomes and Measures

Outcomes were the number of doses of mRNA COVID-19 vaccine received and the factors associated with receipt of at least 4 doses, estimated by hazard ratios (HRs) and 95% Wald CIs via Cox proportional hazards regression. Statistical analyses were conducted between August 9 and 23, 2022.

Results

Overall, 42 697 immunocompromised individuals met the study eligibility criteria. Among these, 18 789 (44.0%) were aged 65 years or older; 20 061 (47.0%) were women and 22 635 (53.0%) were men. With regard to race and ethnicity, 4295 participants (10.1%) identified as Asian or Pacific Islander, 5174 (12.1%) as Black, 14 289 (33.5%) as Hispanic, and 17 902 (41.9%) as White. As of the end of the study period and after accounting for participant censoring due to death or disenrollment from the KPSC health plan, 78.0% of immunocompromised individuals had received a third dose of mRNA COVID-19 vaccine. Only 41.0% had received a fourth dose, which corresponds to a primary series and a monovalent booster dose for immunocompromised individuals. Uptake of a fifth dose was only 0.9% following the US Centers for Disease Control and Prevention (CDC) recommendation to receive a second monovalent booster (ie, fifth dose). Adults aged 65 years or older (HR, 3.95 [95% CI, 3.70-4.22]) were more likely to receive at least 4 doses compared with those aged 18 to 44 years or 45 to 64 years (2.52 [2.36-2.69]). Hispanic and non-Hispanic Black adults (HR, 0.77 [95% CI, 0.74-0.80] and 0.82 [0.78-0.87], respectively, compared with non-Hispanic White adults), individuals with prior documented SARS-CoV-2 infection (0.71 [0.62-0.81] compared with those without), and individuals receiving high-dose corticosteroids (0.88 [0.81-0.95] compared with those who were not) were less likely to receive at least 4 doses.

Conclusions and Relevance

These findings suggest that adherence to CDC mRNA monovalent COVID-19 booster dose recommendations among immunocompromised individuals was low. Given the increased risk for severe COVID-19 in this vulnerable population and the well-established additional protection afforded by booster doses, targeted and tailored efforts to ensure that immunocompromised individuals remain up to date with COVID-19 booster dose recommendations are warranted.

394. Impact of Misdiagnosis of Clostridioides difficile Infection (CDI) by Standard-of-care Specimen Collection and Testing on Estimates of Hospitalized CDI Incidence Among Adults in Louisville, Kentucky, 2019-2020

Background

Public health surveillance indicates that there is a high population-based incidence of laboratory-confirmed hospitalized CDI cases in the United States. Although reported CDI cases are identified via standard-of-care (SOC) specimen collection and CDI testing practices, the impact of SOC misdiagnosis on the reported CDI incidence is uncertain.

Methods

Active surveillance from Oct 14, 2019, to Apr 11, 2020, identified inpatients aged ≥50 years with diarrhea (≥3 stools with Bristol score ≥5 in 24 hours) at all wards at 8 of the 9 adult hospitals in Louisville, Kentucky (population >50 years = 276 456). Study stool specimens from inpatients with diarrhea were screened by rapid GDH/toxin membrane enzyme immunoassay and the positive samples tested by PCR and cell cytotoxicity neutralization assay (CCNA). A study CDI case was a patient with PCR positive/CCNA positive stool or PCR positive stool with pseudomembranous colitis (PMC). Incidence (non-recurrent CDI cases/100 000 persons aged >50 years per year [PY]) was adjusted for the hospitalization share of participating hospitals and, in a sensitivity analysis, for patients with diarrhea without a CDI test result. SOC stool specimen CDI testing occurred independent of the study.

Results

Among 1541 inpatients with diarrhea, study testing identified 109 non-recurrent CDI cases; 18 (16.5%) had PMC, 36 (33.0%) were admitted to intensive care, and 21 (19.3%) died during the 90-day follow-up. Study hospitalized CDI incidence was 154/100 000 PY (202/100 000 PY in the sensitivity analysis). SOC hospitalized CDI incidence was 121/100 000 PY. Of the 109 study CDI cases, 44 (40%) were not SOC-diagnosed (SOC under-diagnosis). Of the 75 SOC CDI cases that also had study testing, 12 (16%) were not study CDI cases (SOC over-diagnosis). SOC-undiagnosed and SOC-diagnosed CDI cases had similar demographics, medical histories, and clinical outcomes. Study testing identified 24% more CDI cases than SOC testing.

Conclusion

There was a high incidence of hospitalized CDI in persons aged >50 years (154-202/100,000 PY). Of the hospitalized CDI cases, one-third were admitted to ICU and one-fifth died. Public health surveillance estimates of the incidence of laboratory-confirmed hospitalized CDI cases, which are based on SOC testing, may be under-estimated by 24%.

Disclosures

Frederick Angulo, DVM PhD, Pfizer: Employee|Pfizer: Stocks/Bonds Joann M. Zamparo, MPH, Pfizer: Employee|Pfizer: Stocks/Bonds Elisa Gonzalez, MPH, Pfizer: Employee|Pfizer: Stocks/Bonds Pingping Zhang, MS, Pfizer: Employee|Pfizer: Stocks/Bonds Michael W. Pride, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds Sharon Gray, MPH, Pfizer: Employee|Pfizer: Stocks/Bonds Catia Matos Ferreira, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds Forest W. Arnold, DO, MSc, Gilead Sciences, Inc.: Grant/Research Support Raul E. Isturiz, MD, Pfizer: Employee|Pfizer: Stocks/Bonds Nadia Minarovic, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds Jennifer Moisi, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds Luis Jodar, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds.

2208. Rates of Medically-Attended RSV among US Adults: A Systematic Review and Meta-Analysis

Background

Adult respiratory syncytial virus (RSV) vaccines are in late stages of development. A comprehensive synthesis of adult RSV burden is needed to inform public health decision-making.

Methods

We performed a systematic review and meta-analysis of studies describing the incidence of medically-attended RSV (MA-RSV) among US adults. We also identified studies reporting nasopharyngeal (NP) or nasal swab RT-PCR results with paired serology (four-fold-rise) or sputum (RT-PCR) to calculate RSV detection ratios quantifying improved diagnostic yield after adding a second specimen type (ie, serology or sputum).

Results

We identified 14 studies with 15 unique MA-RSV incidence estimates, all based on NP or nasal swab RT-PCR testing alone. Pooled annual RSV-associated incidence per 100,000 adults ≥65 years of age was 178 (95%CI: 152‒204; n=8 estimates) hospitalizations (4 prospective studies: 189; 4 model-based studies: 157), 133 (95%CI: 0‒319, n=2) emergency department (ED) admissions, and 1519 (95%CI: 1109‒1929, n=3) outpatient visits. Based on 6 studies, RSV detection was ∼1.5 times higher when adding paired serology or sputum. After adjustment for this increased yield, annual RSV-associated rates per 100,000 adults ≥65 years were 267 hospitalizations (UI: 228‒306) (prospective: 282; model-based: 236), 200 ED admissions (UI: 0‒478), and 2278 outpatient visits (UI: 1663‒2893). Persons < 65 years with chronic medical conditions were 1.2−28 times more likely to be hospitalized for RSV depending on risk condition.

Conclusion

The true burden of RSV has been underestimated and is significant among older adults and individuals with chronic medical conditions. A highly effective adult RSV vaccine would have substantial public-health impact.

Disclosures

John M. McLaughlin, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds Farid L. Khan, MPH, Pfizer: Employee|Pfizer: Stocks/Bonds Elizabeth Begier, M.D., M.P.H., Pfizer: Employee|Pfizer: Stocks/Bonds David Swerdlow, MD, Pfizer: Advisor/Consultant|Pfizer: Stocks/Bonds Luis Jodar, PhD, Pfizer: Employee|Pfizer: Stocks/Bonds Ann R. Falsey, MD, BioFire Diagnostics: Grant/Research Support|Janssen: Grant/Research Support|Merck, Sharp and Dohme: Grant/Research Support|Novavax: Advisor/Consultant|Pfizer: Grant/Research Support.

Estimated BNT162b2 Vaccine Effectiveness Against Infection With Delta and Omicron Variants Among US Children 5 to 11 Years of Age

IMPORTANCE

Data describing the vaccine effectiveness (VE) and durability of BNT162b2 among children 5 to 11 years of age are needed.

OBJECTIVE

To estimate BNT162b2 VE against SARS-CoV-2 infection among children aged 5 to 11 years during Delta and Omicron variant-predominant periods and to further assess VE according to prior SARS-CoV-2 infection status and by sublineage during the Omicron variant-predominant period.

DESIGN, SETTING, AND PARTICIPANTS

This test-negative case-control study was conducted from November 2 to December 9, 2021 (Delta variant), and from January 16 to September 30, 2022 (Omicron variant), among 160 002 children tested at a large national US retail pharmacy chain, for SARS-CoV-2 via polymerase chain reaction (PCR); 62 719 children were tested during the Delta period, and 97 283 were tested during the Omicron period.

EXPOSURE

Vaccination with BNT162b2 before SARS-CoV-2 testing vs no vaccination.

MAIN OUTCOMES AND MEASURES

The primary outcome was SARS-CoV-2 infection confirmed by PCR (regardless of the presence of symptoms), and the secondary outcome was confirmed symptomatic infection. Adjusted estimated VE was calculated from multilevel logistic regression models.

RESULTS

A total of 39 117 children tested positive and 131 686 tested negative for SARS-CoV-2 (total, 170 803; 84 487 [49%] were boys; mean [SD] age was 9 [2] years; 74 236 [43%] were White non-Hispanic or non-Latino; and 37 318 [22%] were Hispanic or Latino). Final VE analyses included 160 002 children without SARS-CoV-2 infection less than 90 days prior. The VE of 2 doses of BNT162b2 against Delta was 85% (95% CI, 80%-89%; median follow-up, 1 month) compared with the Omicron period (20% [95% CI, 17%-23%]; median follow-up, 4 months). The adjusted VE of 2 doses against Omicron at less than 3 months was 39% (95% CI, 36%-42%), and at 3 months or more, it was -1% (95% CI, -6% to 3%). Protection against Omicron was higher among children with vs without infection 90 days or more prior but decreased in all children approximately 3 months after the second dose (58% [95% CI, 49%-66%] with infection vs 37% [95% CI, 34%-41%] without infection at <3 months; 27% [95% CI, 17%-35%] with infection vs -7% [95% CI, -12% to -1%] at ≥3 months without infection). The VE of 2 doses of BNT162b2 at less than 3 months by Omicron sublineage was 40% (95% CI, 36%-43%) for BA.1, 32% (95% CI, 21%-41%) for BA.2/BA.2.12.1, and 50% (95% CI, 37%-60%) for BA.4/BA.5. After 3 months or more, VE was nonsignificant for BA.2/BA.2.12.1 and BA.4/BA.5. The VE of a booster dose was 55% (95% CI, 50%-60%) against Omicron, with no evidence of waning at 3 months or more.

CONCLUSIONS AND RELEVANCE

This study suggests that, among children aged 5 to 11 years, 2 doses of BNT162b2 provided modest short-term protection against Omicron infection that was higher for those with prior infection; however, VE waned after approximately 3 months in all children. A booster dose restored protection against Omicron and was maintained for at least 3 months. These findings highlight the continued importance of booster vaccination regardless of history of prior COVID-19.

Systematic Review and Meta-analysis of Lyme Disease Data and Seropositivity for Borrelia burgdorferi, China, 2005‒2020

Since its initial identification in 1986, Lyme disease has been clinically diagnosed in 29 provinces in China; however, national incidence data are lacking. To summarize Lyme disease seropositivity data among persons across China, we conducted a systematic literature review of Chinese- and English-language journal articles published during 2005‒2020. According to 72 estimates that measured IgG by using a diagnostic enzyme-linked assay (EIA) alone, the seropositivity point prevalence with a fixed-effects model was 9.1%. A more conservative 2-tier testing approach of EIA plus a confirmatory Western immunoblot (16 estimates) yielded seropositivity 1.8%. Seropositivity by EIA for high-risk exposure populations was 10.0% and for low-risk exposure populations was 4.5%; seropositivity was highest in the northeastern and western provinces. Our analysis confirms Lyme disease prevalence, measured by seropositivity, in many Chinese provinces and populations at risk. This information can be used to focus prevention measures in provinces where seropositivity is high.

Immunogenicity of a 20-valent pneumococcal conjugate vaccine in adults 18 to 64 years old with medical conditions and other factors that increase risk of pneumococcal disease

CLINICAL TRIAL REGISTRATION

NCT03760146, NCT03828617.

Coronavirus Disease 2019 Severity and Risk of Subsequent Cardiovascular Events

BACKGROUND

Little is known about the relationship between coronavirus disease 2019 (COVID-19) severity and subsequent risk of experiencing a cardiovascular event (CVE) after COVID-19 recovery. We evaluated this relationship in a large cohort of United States adults.

METHODS

Using a claims database, we performed a retrospective cohort study of adults diagnosed with COVID-19 between 1 April 2020 and 31 May 2021. We evaluated the association between COVID-19 severity and risk of CVE >30 days after COVID-19 diagnosis using inverse probability of treatment-weighted competing risks regression. Severity was based on level of care required for COVID-19 treatment: intensive care unit (ICU) admission, non-ICU hospitalization, or outpatient care only.

RESULTS

A total of 1 357 518 COVID-19 patients were included (2% ICU, 3% non-ICU hospitalization, and 95% outpatient only). Compared to outpatients, there was an increased risk of any CVE for patients requiring ICU admission (adjusted hazard ratio [aHR], 1.80 [95% confidence interval {CI}, 1.71-1.89]) or non-ICU hospitalization (aHR, 1.28 [95% CI, 1.24-1.33]). Risk of subsequent hospitalization for CVE was even higher (aHRs, 3.47 [95% CI, 3.20-3.76] for ICU and 1.96 [95% CI, 1.85-2.09] for non-ICU hospitalized vs outpatient only).

CONCLUSIONS

COVID-19 patients hospitalized or requiring critical care had a significantly higher risk of experiencing and being hospitalized for post-COVID-19 CVE than patients with milder COVID-19 who were managed solely in the outpatient setting, even after adjusting for differences between these groups. These findings underscore the continued importance of preventing severe acute respiratory syndrome coronavirus 2 infection from progressing to severe illness to reduce potential long-term cardiovascular complications.

Polysaccharide and conjugate vaccines to Streptococcus pneumoniae generate distinct humoral responses

Streptococcus pneumoniae is a major cause of community-acquired pneumonia, bacteremia, and meningitis in older adults worldwide. Two pneumococcal vaccines containing S. pneumoniae capsular polysaccharides are in current use: the polysaccharide vaccine PPSV23 and the glycoconjugate vaccine PCV13. In clinical trials, both vaccines elicit similar opsonophagocytic killing activity. In contrast to polysaccharide vaccines, conjugate vaccines have shown consistent efficacy against nasopharyngeal carriage and noninvasive pneumonia overall and for some prevalent individual serotypes. Given these different clinical profiles, it is crucial to understand the differential immunological responses induced by these two vaccines. Here, we used a high-throughput systems serology approach to profile the biophysical and functional features of serum antibodies induced by PCV13 and PPSV23 at 1 month and 1 year. In comparison with PPSV23, PCV13 induced higher titers across antibody isotypes; more durable antibody responses across immunoglobulin G (IgG), IgA, and IgM isotypes; and increased antigenic breadth. Although titers measured in opsonophagocytic activity (OPA) assays were similar between the two groups, confirming what was observed in clinical studies, serum samples from PCV13 vaccinees could induce additional non-OPA antibody-dependent functions, including monocyte phagocytosis and natural killer cell activation. In a multivariate modeling approach, distinct humoral profiles were demonstrated in each arm. Together, these results demonstrate that the glycoconjugate PCV13 vaccine induces an antigenically broader, more durable, polyfunctional antibody response. These findings may help explain the increased protection against S. pneumoniae colonization and noninvasive pneumonia and the longer duration of protection against invasive pneumococcal disease, mediated by PCV13.

Effectiveness Associated With BNT162b2 Vaccine Against Emergency Department and Urgent Care Encounters for Delta and Omicron SARS-CoV-2 Infection Among Adolescents Aged 12 to 17 Years

Importance

Data about the duration of protection of 2 and 3 doses of BNT162b2 in children and adolescents are needed to help inform recommendations for boosters in this age group.

Objective

To evaluate vaccine effectiveness (VE) and durability associated with 2 doses of BNT162b2 against Delta- and Omicron-related emergency department (ED) and urgent care (UC) encounters among adolescents aged 12 to 17 years and to estimate VE associated with 3 doses against these same outcomes.

Design, Setting, and Participants

This test-negative case-control study was conducted at Kaiser Permanente Southern California, an integrated health care system using electronic health records in the US. Participants included Kaiser Permanente Southern California members ages 12 to 17 years with an ED or UC encounter from November 1, 2021, through March 18, 2022, for acute respiratory infection who were tested for SARS-CoV-2 via a reverse transction-polymerase chain reaction test. Analyses were conducted from March 21 to June 22, 2022.

Exposures

BNT162b2 vaccination status ascertained from electronic health records and state registry data.

Main Outcomes and Measures

The main outcome was VE associated with BNT162b2 against ED and UC encounters related to Delta or Omicron variant SARS-CoV-2 infection.

Results

Analyses were conducted among 3168 adolescents, including 1004 with ED visits and 2164 with UC visits. Median (IQR) age was 15 (13-16) years, and 1461 (46.1%) were boys. In adjusted analyses, VE associated with 2 doses of BNT162b2 against ED or UC encounters was highest within the first 2 months for both Delta (89% [95% CI, 69% to 96%]) and Omicron (73% [95% CI, 54% to 84%]) variants but waned to 49% (95% CI, 27% to 65%) for the Delta variant and 16% (95% CI, -7% to 34%) for the Omicron variant at 6 months and beyond. A third dose of BNT162b2 was associated with improved protection against the Omicron variant (87% [95% CI, 72% to 94%]) after a median (IQR) of 19 (9-32) days after dose 3.

Conclusions and Relevance

These findings suggest that 2 doses of the BNT162b2 COVID-19 vaccine were associated with high levels of protection against ED and UC encounters related to the Delta and Omicron variants of SARS-CoV-2 in the first few months after vaccination. However, effectiveness waned over time, especially against Omicron. A third dose of BNT162b2 was associated with improved protection against Omicron beyond that seen initially after 2 doses, underscoring the importance of boosters for adolescents aged 12 to 17 years.

Distribution of Serotypes Causing Invasive Pneumococcal Disease in Children From High-Income Countries and the Impact of Pediatric Pneumococcal Vaccination

BACKGROUND

The introduction and adoption of pneumococcal conjugate vaccines (PCVs) into pediatric national immunization programs (NIPs) has led to large decreases in invasive pneumococcal disease (IPD) incidence caused by vaccine serotypes. Despite these reductions, the global IPD burden in children remains significant.

METHODS

We collected serotype-specific IPD data from surveillance systems or hospital networks of all 30 high-income countries that met inclusion criteria. Data sources included online databases, surveillance system reports, and peer-reviewed literature. Percentage of serotyped cases covered were calculated for all countries combined and by PCV type in the pediatric NIP.

RESULTS

We identified 8012 serotyped IPD cases in children <5 or ≤5 years old. PCV13 serotype IPD caused 37.4% of total IPD cases, including 57.1% and 25.2% for countries with PCV10 or PCV13 in the pediatric NIP, respectively, most commonly due to serotypes 3 and 19A (11.4% and 13.3%, respectively, across all countries). In PCV10 countries, PCV15 and PCV20 would cover an additional 45.1% and 55.6% of IPD beyond serotypes contained in PCV10, largely due to coverage of serotype 19A. In PCV13 countries, PCV15 and PCV20 would cover an additional 10.6% and 38.2% of IPD beyond serotypes contained in PCV13. The most common IPD serotypes covered by higher valency PCVs were 10A (5.2%), 12F (5.1%), and 22F and 33F (3.5% each).

CONCLUSIONS

Much of the remaining IPD burden is due to serotypes included in PCV15 and PCV20. The inclusion of these next generation PCVs into existing pediatric NIPs may further reduce the incidence of childhood IPD.

Durability of BNT162b2 vaccine against hospital and emergency department admissions due to the omicron and delta variants in a large health system in the USA: a test-negative case-control study

BACKGROUND

The duration of protection against the omicron (B.1.1.529) variant for current COVID-19 vaccines is not well characterised. Vaccine-specific estimates are especially needed. We aimed to evaluate the effectiveness and durability of two and three doses of the BNT162b2 (Pfizer-BioNTech) mRNA vaccine against hospital and emergency department admissions due to the delta (B.1.617.2) and omicron variants.

METHODS

In this case-control study with a test-negative design, we analysed electronic health records of members of Kaiser Permanente Southern California (KPSC), a large integrated health system in California, USA, from Dec 1, 2021, to Feb 6, 2022. Vaccine effectiveness was calculated in KPSC patients aged 18 years and older admitted to hospital or an emergency department (without a subsequent hospital admission) with a diagnosis of acute respiratory infection and tested for SARS-CoV-2 via PCR. Adjusted vaccine effectiveness was estimated with odds ratios from adjusted logistic regression models. This study is registered with ClinicalTrials.gov (NCT04848584).

FINDINGS

Analyses were done for 11 123 hospital or emergency department admissions. In adjusted analyses, effectiveness of two doses of the BNT162b2 vaccine against the omicron variant was 41% (95% CI 21-55) against hospital admission and 31% (16-43) against emergency department admission at 9 months or longer after the second dose. After three doses, effectiveness of BNT162b2 against hospital admission due to the omicron variant was 85% (95% CI 80-89) at less than 3 months but fell to 55% (28-71) at 3 months or longer, although confidence intervals were wide for the latter estimate. Against emergency department admission, the effectiveness of three doses of BNT162b2 against the omicron variant was 77% (72-81) at less than 3 months but fell to 53% (36-66) at 3 months or longer. Trends in waning against SARS-CoV-2 outcomes due to the delta variant were generally similar, but with higher effectiveness estimates at each timepoint than those seen for the omicron variant.

INTERPRETATION

Three doses of BNT162b2 conferred high protection against hospital and emergency department admission due to both the delta and omicron variants in the first 3 months after vaccination. However, 3 months after receipt of a third dose, waning was apparent against SARS-CoV-2 outcomes due to the omicron variant, including hospital admission. Additional doses of current, adapted, or novel COVD-19 vaccines might be needed to maintain high levels of protection against subsequent waves of SARS-CoV-2 caused by the omicron variant or future variants with similar escape potential.

FUNDING

Pfizer.

Population-based incidence of hospitalized Clostridioides difficile infection among older adults in Ota-ku, Japan: A prospective surveillance study

OBJECTIVES

Clostridioides difficile infection (CDI) burden is not well-characterized in Japan. Therefore, we conducted a population-based, hospitalized CDI incidence study, compared the results with standard-of-care (SOC) CDI testing, and generalized the results for nationwide incidence estimates.

METHODS

Surveillance identified inpatients ≥50 years-of-age with diarrhea in nine Tokyo hospitals from December 17, 2018-March 30, 2020. A CDI case was defined as a patient with a PCR-positive/cell cytotoxicity neutralization assay (CCNA)-positive stool or a PCR-positive stool and pseudomembranous colitis (PMC). Incidence estimates were adjusted for the hospitalization share of participating hospitals and, in the sensitivity analysis, for missing CDI test results. SOC specimen collection and CDI testing occurred independently.

RESULTS

Surveillance during 318 840 patient-days identified 4633 inpatients with diarrhea. Sixty-three CDI cases were identified; 11 (17·5%) had PMC, eight (12·7%) recurrent CDI, and nine (14·3%) died. The hospitalized CDI incidence was 97/100 000 population per year (PPY) in persons ≥50 years-of-age and, in the sensitivity analysis, 324/100 000 PPY. The incidence was 170 and 481/100 000 PPY in persons ≥65 and ≥ 85 years-of-age, respectively; these estimates increased to 569 and 1609/100 000 PPY in the sensitivity analysis, respectively. There were 12 primary SOC CDI cases in persons ≥50 years-of-age (18/100 000 PPY).

CONCLUSIONS

The CDI incidence was high in older adults, with severe clinical consequences. SOC specimen collection and testing under-estimated CDI burden. There are >57 000 hospitalized CDI cases per year in Japan in persons ≥50 years-of-age. Public health interventions are needed to reduce the CDI burden in Japan.

US County-level COVID-19 Vaccine Uptake and Rates of Omicron Cases and Deaths

The population-level impact of vaccination on Omicron-related disease is not well described. We fit negative binomial models to estimate the relationship between US county-level vaccine coverage and rates of coronavirus disease 2019. Increased booster dose uptake was associated with lower rates of Omicron cases and deaths and is critical to combat future severe acute respiratory syndrome coronavirus 2 waves.

Rates of Medically-Attended RSV among US Adults: A Systematic Review and Meta-Analysis

Background

Adult respiratory syncytial virus (RSV) vaccines are in late stages of development. A comprehensive synthesis of adult RSV burden is needed to inform public health decision-making.

Methods

We performed a systematic review and meta-analysis of studies describing the incidence of medically-attended RSV (MA-RSV) among US adults. We also identified studies reporting nasopharyngeal (NP) or nasal swab RT-PCR results with paired serology (four-fold-rise) or sputum (RT-PCR) to calculate RSV detection ratios quantifying improved diagnostic yield after adding a second specimen type (ie, serology or sputum).

Results

We identified 14 studies with 15 unique MA-RSV incidence estimates, all based on NP or nasal swab RT-PCR testing alone. Pooled annual RSV-associated incidence per 100,000 adults ≥65 years of age was 178 (95%CI: 152‒204; n = 8 estimates) hospitalizations (4 prospective studies: 189; 4 model-based studies: 157), 133 (95%CI: 0‒319, n = 2) emergency department (ED) admissions, and 1519 (95%CI: 1109‒1929, n = 3) outpatient visits. Based on 6 studies, RSV detection was ∼1.5 times higher when adding paired serology or sputum. After adjustment for this increased yield, annual RSV-associated rates per 100,000 adults ≥65 years were 267 hospitalizations (UI: 228‒306) (prospective: 282; model-based: 236), 200 ED admissions (UI: 0‒478), and 2278 outpatient visits (UI: 1663‒2893). Persons &lt;65 years with chronic medical conditions were 1.2−28 times more likely to be hospitalized for RSV depending on risk condition.

Conclusions

The true burden of RSV has been underestimated and is significant among older adults and individuals with chronic medical conditions. A highly effective adult RSV vaccine would have substantial public-health impact.

Correction: Theilacker et al. PCV13 Vaccination of Adults against Pneumococcal Disease: What We Have Learned from the Community-Acquired Pneumonia Immunization Trial in Adults (CAPiTA). Microorganisms 2022, 10, 127

The authors wish to make the following corrections to this paper [...]

County-level vaccination coverage and rates of COVID-19 cases and deaths in the United States: An ecological analysis

Background

On Dec 14, 2020, the United States initiated a nationwide COVID-19 vaccination campaign. Demonstrating clear population-level impact following vaccine introduction helps to further elucidate and quantify the public-health benefits of vaccination.

Methods

Using a negative binomial regression model we evaluated the ecological association between county-level COVID-19 vaccine uptake and rates of COVID-19 cases and deaths in the United States from April 1, 2021 through October 31, 2021 controlling for a broad set of county-level environmental, sociodemographic, economic, and health-status-related characteristics. County-level data were obtained from several publicly available databases that were merged for analysis.

Findings

After adjustment for county-level characteristics, US counties with ≥ 80% of their residents ≥ 12 years of age fully vaccinated against COVID-19 had 30% (95% CI: 25−35; P < .001) and 46% (38−52; P < .001) lower rates of COVID-19 cases and deaths, respectively, versus those with <50% coverage (reference group). A dose response was observed: counties with 70−79% uptake had 20% (95% CI: 16−24; P < .001) and 35% (29−40; P < .001) lower rates of cases and deaths, respectively; counties with 60−69% uptake had 8% (5−11; P < .001) and 20% (15−24; P < .001) lower rates; and counties with 50−59% uptake had 2% (0−4; P =.09) and 8% (4−12; P < .001) lower rates. Restricting the analysis to the period when the Delta variant was predominant (June 1, 2021 ‒ October 31, 2021) showed similar findings.

Interpretation

Our results showed that US counties with higher proportions of persons ≥ 12 years of age fully vaccinated against COVID-19 had substantially lower rates of COVID-19 cases and deaths—a finding that showed dose response and persisted even in the period when Delta was predominant.

Funding

Pfizer.

Effectiveness of a third dose of BNT162b2 mRNA COVID-19 vaccine in a large US health system: A retrospective cohort study

Background

Globally, recommendations are expanding for third (booster) doses of BNT162b2 (Pfizer-BioNTech). In the United States, as of November 19, 2021, boosters were recommended for all adults aged 18 years and older. We evaluated the effectiveness of a third dose of BNT162b2 among adults in a large US integrated health system.

Methods

In this retrospective cohort study, we analyzed electronic health records from Kaiser Permanente Southern California between Dec 14, 2020 and Dec 5, 2021 to assess vaccine effectiveness (VE) of two and three doses of BNT162b2 against SARS-CoV-2 infections (without hospital admission) andCOVID-19-related hospital admission. VE was calculated using hazards ratios from adjusted Cox models.

Findings

After only two doses, VE against infection declined from 85% (95% CI 83-86) during the first month to 49% (46-51) ≥ 7 months following vaccination. Overall VE against hospitalization was 90% (95% CI 86-92) within one month and did not wane, however, effectiveness against hospitalization appeared to wane among immunocompromised individuals but was not statistically significant (93% [72-98] at 1 month to 74% [45-88] after ≥ 7 months; p=0·490). Three-dose VE (median follow-up 1·3 months [SD 0·6]) was 88% (95% CI 86-89) against infection and 97% (95-98) against hospitalization. Effectiveness after three doses was higher than that seen one month after receiving only two doses for both outcomes. Relative VE of three doses compared to two (with at least six months after the second dose) was 75% (95% CI 71-78) against infections and 70% (48-83) against hospital admissions.

Interpretation

These data support the benefit of broad BNT162b2 booster recommendations, as three doses confers comparable, if not better, protection against SARS-CoV-2 infections and hospital admission as was seen soon after receiving two doses.

Funding

Pfizer Inc.

Correlates of protection for meningococcal surface protein vaccines; current approaches for the determination of breadth of coverage

INTRODUCTION

The two currently licensed surface protein non capsular meningococcal serogroup B (MenB) vaccines both have the purpose of providing broad coverage against diverse MenB strains. However, the different antigen compositions and approaches used to assess breadth of coverage currently make direct comparisons complex.

AREAS COVERED

In the second of two companion papers, we comprehensively review the serology and factors influencing breadth of coverage assessments for two currently licensed MenB vaccines.

EXPERT OPINION

Surface protein MenB vaccines were developed using different approaches, resulting in unique formulations and thus their breadth of coverage. The surface proteins used as vaccine antigens can vary among meningococcal strains due to gene presence/absence, sequence diversity and differences in protein expression. Assessment of the breadth of coverage provided by vaccines is influenced by the ability to induce cross-reactive functional immune responses to sequence diverse protein variants; the characteristics of the circulating invasive strains from specific geographic locations; methodological differences in the immunogenicity assays; differences in human immune responses between individuals; and the maintenance of protective antibody levels over time. Understanding the proportion of meningococcal strains which are covered by the two licensed vaccines is important in understanding protection from disease and public health use.