1. Hospitalization Rates Following mRNA SARS-CoV-2 Booster Vaccination among Patients with and without Prior SARS-CoV-2 Infection: A Nationwide, Retrospective Cohort Study
- Author
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Chunlei Zheng, Westyn Branch-Elliman, Nathanael R Fillmore, and Paul A Monach
- Abstract
Background We previously reported a transient increased risk of hospitalization after mRNA vaccination among patients with prior SARS-CoV-2, absolute risk ~ 1:1000. Here, we extend and expand this analysis to evaluate the impact of prior infection on hospitalization after a third (booster) dose. Methods Nationwide, retrospective cohort study of hospitalization among US Veterans who received a third dose of mRNA vaccine between 7/1/2021-2/28/2022. Daily rates of incident hospitalization were compared before and after booster doses, stratified by history of SARS-CoV-2. Results 1,632,806 patients received a third dose, including 90,174 with a history of SARS-CoV-2 infection. Hospitalization rates were unchanged before and after the booster dose among patients with (112.3/100,000 post-dose versus 100.2/100,000 pre-dose, p = 0.24) or without previous infection (32.1/100,000 post-dose versus 31.3/100,000 pre-dose, p = 0.71). Among 241 patients hospitalized after receipt of the initial vaccination, 90 received a booster, and none of these 90 patients were hospitalized. Conclusions There was not convincing evidence for increased hospitalizations shortly after booster vaccines, including in patients with a history of SARS-CoV-2 infection who required hospitalization after their initial vaccine. The size and design of the study prevent strong conclusions about absence of risk.
- Published
- 2023
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