Co-Administration of BNT162b2 COVID-19 and Influenza Vaccines in Adults: A Global Systematic Review

Background/Objectives: Co-administration of BNT162b2 with licensed seasonal influenza vaccines (SIVs) is recommended by health authorities. We provide a comprehensive summary of the data supporting this practice in adults. Method(s): This systematic review consolidates available evidence on the prevalence, safety, immunogenicity, efficacy, and effectiveness of co-administering BNT162b2 and SIVs. Searches were conducted for English studies in adults >= 18 years of age between January 2021 and August 2024, with no geographic restriction. Study quality was assessed using Cochrane RoB 2.0 and the Newcastle-Ottawa Scale. Result(s): Twenty studies (15 observational and 5 clinical trials) were included, mainly conducted in seven countries in Europe and North America. Eight observational studies reported prevalence, twelve reported safety/reactogenicity, six reported immunogenicity, and three evaluated efficacy/effectiveness. Reported co-administration of BNT162b2 vaccines with SIVs increased over time. Of persons receiving BNT162b2, the proportion that reported co-administered SIVs increased from 2.7% in 2021 to 34.1% in 2023. Although variability in outcomes was observed, no consistent pattern indicating a negative impact on immunogenicity from same-day co-administration was identified. Effectiveness was not observed to change when BNT162B2 was co-administered with SIVs. The incidence of systemic and local adverse events was comparable between individuals receiving the vaccines separately and those receiving them co-administered. Conclusion(s): The findings from this review indicate that the co-administration of BNT162B2 with SIVs is both safe and effective. This highlights the value of co-administration, which could enhance vaccine uptake by streamlining immunization protocols and reducing health visits. Copyright © 2025 by the authors.