Postvaccination SARS-CoV-2 infection among healthcare workers: A systematic review and meta-analysis

Healthcare workers (HCWs) remain on the front line of the battle against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus disease 2019 (COVID-19) infection and are among the highest groups at risk of infection during this raging pandemic. We conducted a systematic review and meta-analysis to assess the incidence of postvaccination SARS-CoV-2 infection among vaccinated HCWs. We searched multiple databases from inception through August 2021 to identify studies that reported on the incidence of postvaccination SARS-CoV-2 infection among HCWs. Meta-analysis was performed to determine pooled proportions of COVID-19 infection in partially/fully vaccinated as well as unvaccinated individuals. Eighteen studies with 228 873 HCWs were included in the final analysis. The total number of partially vaccinated, fully vaccinated, and unvaccinated HCWs were 132 922, 155 673, and 17 505, respectively. Overall pooled proportion of COVID-19 infections among partially/fully vaccinated and unvaccinated HCWs was 2.1% (95% confidence interval [CI] 1.2-3.5). Among partially vaccinated, fully vaccinated and unvaccinated HCWs, pooled proportion of COVID-19 infections was 2.3% (CI 1.2-4.4), 1.3% (95% CI 0.6-2.9), and 10.1% (95% CI 4.5-19.5), respectively. Our analysis shows the risk of COVID-19 infection in both partially and fully vaccinated HCWs remains exceedingly low when compared to unvaccinated individuals. There remains an urgent need for all frontline HCWs to be vaccinated against SARS-CoV-2 infection.