Abstract
With the COVID-19 pandemic ongoing, accurate assessment of population immunity and the effectiveness of booster and enhancer vaccine doses is critical. We compare COVID-19-related hospitalization incidence rates in 2,412,755 individuals across four exposure levels: non-recent vaccine immunity (two BNT162b2 COVID-19 vaccine doses five or more months prior), boosted vaccine immunity (three BNT162b2 doses), infection-induced immunity (previous COVID-19 without a subsequent BNT162b2 dose), and enhanced infection-induced immunity (previous COVID-19 with a subsequent BNT162b2 dose). Rates, adjusted for potential demographic, clinical and health-seeking-behavior confounders, were assessed from July-November 2021 when the Delta variant was predominant. Compared with non-recent vaccine immunity, COVID-19-related hospitalization incidence rates were reduced by 89% (87-91%) for boosted vaccine immunity, 66% (50-77%) for infection-induced immunity and 75% (61-83%) for enhanced infection-induced immunity. We demonstrate that infection-induced immunity (enhanced or not) provides more protection against COVID-19-related hospitalization than non-recent vaccine immunity, but less protection than booster vaccination. Additionally, our results suggest that vaccinating individuals with infection-induced immunity further enhances their protection.
【초록키워드】 COVID-19, COVID-19 vaccine, Immunity, Hospitalization, COVID-19 pandemic, delta variant, vaccine dose, BNT162b2, Effectiveness, incidence rate, population immunity, Critical, booster, booster vaccination, dose, individual, confounders, doses, enhancer, vaccine immunity, FIVE, ENhance, subsequent, reduced, adjusted, provide, less, predominant, were assessed, 【제목키워드】 Hospitalization, Vaccine-induced immunity, individual,