Effectiveness of BNT162b2 COVID-19 Vaccination in Children Aged 5–17 Years in the United States

Importance COVID-19 vaccines are authorized for use in children in the United States; real-world assessment of vaccine effectiveness in children is needed. Objective To estimate the effectiveness of receiving a complete primary series of monovalent BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine in US children. Design A cohort study of children aged 5–17 years vaccinated with BNT162b2 matched with unvaccinated children. Setting Participants identified in Optum and CVS Health insurance administrative claims databases were linked with Immunization Information System (IIS) COVID-19 vaccination records from 16 US jurisdictions between December 11, 2020, and May 31, 2022 (end date varied by database and IIS). Participants Vaccinated children were followed from their first BNT162b2 dose and matched to unvaccinated children on calendar date, US county of residence, and demographic and clinical factors. Censoring occurred if vaccinated children failed to receive a timely dose 2 or if unvaccinated children received any dose. Exposure BNT162b2 vaccinations were identified using IIS vaccination records and insurance claims. Main Outcomes and Measures Two COVID-19 outcome definitions were evaluated: COVID-19 diagnosis in any medical setting and COVID-19 diagnosis in hospitals/emergency departments (EDs). Propensity score-weighted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated with Cox proportional hazards models, and vaccine effectiveness (VE) was estimated as 1 minus HR. VE was estimated overall, within age subgroups, and within variant-specific eras. Sensitivity, negative control, and quantitative bias analyses evaluated various potential biases. Results There were 453,655 eligible vaccinated children one-to-one matched to unvaccinated comparators (mean age 12 years; 50% female). COVID-19 hospitalizations/ED visits were rare in children, regardless of vaccination status (Optum, 41.2 per 10,000 person-years; CVS Health, 44.1 per 10,000 person-years). Overall, vaccination was associated with reduced incidence of any medically diagnosed COVID-19 (meta-analyzed VE = 38% [95% CI, 36%-40%]) and hospital/ED–diagnosed COVID-19 (meta-analyzed VE = 61% [95% CI, 56%-65%]). VE estimates were lowest among children 5–11 years and during the omicron variant era. Conclusions and Relevance Receipt of a complete BNT162b2 vaccine primary series was associated with overall reduced medically diagnosed COVID-19 and hospital/ED–diagnosed COVID-19 in children; observed VE estimates differed by age group and variant era. Question Does receiving a complete primary series of monovalent BNT162b2 COVID-19 vaccine reduce COVID-19 diagnoses and ED visits/hospitalizations in children aged 5–17 years? Findings In this cohort study evaluating vaccination records and medical encounters from 827,149 children, recipients of a complete primary series of BNT162b2 generally had lower rates of COVID-19 diagnoses and ED visits/hospitalizations than unvaccinated children. Vaccine effectiveness was lower in children aged 5–11 years and during omicron variant predominance. Meaning Receiving a primary series of monovalent BNT162b2 COVID-19 vaccine is effective in preventing COVID-19 diagnoses; changing variants and younger age groups may require further evaluations. ### Competing Interest Statement RPO, RP, JD, MM, JS, LBW, LP, EJB, GY, KLA, and JDS are employees of Optum and may own stock in UnitedHealth Group. JBL, CLB, and MSA are employees of RTI International, an independent, not-for-profit research institute that performs research on behalf of governmental and commercial clients, including pharmaceutical and vaccine manufacturers. CNM and DAD are employees of CVS Health. PCL, YJ, HLW, JG, ACL, KM, MW, TCC, SC, RAF, SAA, YC, and AS have no conflicts of interest to declare. ### Clinical Protocols ### Funding Statement This work was supported by the U.S. Food and Drug Administration. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This surveillance activity was conducted as part of the FDA public health surveillance mandate and was not subject to Institutional Review Board oversight. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data that has been used is confidential.