AUTHOR=Mangat Halinder S. , Musah Anwar , Luedtke Susanne , Syed Akheel A. , Maramattom Boby V. , Maruthanal Joel , Bosman Arnold , Kostkova Patty 

TITLE=Analyses of reported severe adverse events after immunization with SARS-CoV-2 vaccines in the United States: One year on

JOURNAL=Frontiers in Public Health

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2022.972464

DOI=10.3389/fpubh.2022.972464

ISSN=2296-2565

ABSTRACT=Objective: To analyze rates of reported sAEFI attributed to SARS/nCOV2 vaccines in the United States (US) using safety surveillance data.
Methods: Observational study of severe adverse events after immunization (sAEFI) reported to the vaccine adverse events reporting system (VAERS) between December 13, 2020, to December 13, 2021, and attributed to SARS/nCoV2 vaccination programs across all US states and territories was obtained. All sAEFI in conjunction with mRNA (BNT-162b or mRNA-1273) or adenovector (Ad26.COV2.S) vaccines were included. The 28-day crude cumulative rates for ‘reported’ emergency department (ED) visits and sAEFI viz. hospitalizations, life-threatening events and deaths following SARS/nCoV2 vaccination were calculated. Incidence rate ratios (IRRs) of reported sAEFI were compared between mRNA and adenovector vaccines using generalized Poisson regression models. 
Results: During the study period, 485 million SARS/nCoV2 vaccines doses were administered nationwide, and 88,626 sAEFI reported in VAERS. The 28-day crude cumulative reporting rates per 100,000 doses were 14.97 (95% CI, 14.86–18.38) for ED visits, 5.32 (5.26–5.39) for hospitalizations, 1.72 (1.68–1.76) for life-threatening events, and 1.08 (1.05–1.11) for deaths. Females had two-fold rates for any reported AEFI compared to males, but lower adjusted IRRs for sAEFI. Cumulative rates per dose for reported sAEFI attributed to adenovector vaccine were 2–3-fold higher, and adjusted IRRs 1.5-fold higher than mRNA vaccines.
Conclusions: Overall cumulative rates for reported sAEFI following SARS/nCoV2 vaccination in US over 1 year were very low; single-dose adenovector vaccine had 1.5-fold higher adjusted rates for reported sAEFI, which may however equate with multiple-doses mRNA vaccine regimens. These data indicate absence of high risks of sAEFI following SARS/nCoV2 vaccines and support safety equipoise between mRNA and adenovector vaccines. Public health messaging of these data is critical to overcome heuristic biases. Furthermore, these data may support ongoing adenovector vaccine use, especially in low- and middle-income countries due to affordability, logistical and cold chain challenges.