The initial impact of a national BNT162b2 mRNA COVID-19 vaccine rollout

Zaqout, A.; Daghfal, J.; Alaqad, I.; Hussein, S.; Aldushain, A.; Almaslamani, M.; Abukhattab, M.; Omrani, A. S.

Objective We herein report the initial impact of a national BNT162b2 rollout on SARS-CoV-2 infections in Qatar. Methods We included all individuals who by 16 March 2021 had completed 14 days of follow up after the receipt of BNT162b2. We calculated incidence rates (IR) and their 95% confidence intervals (CI), during days 1-7, 8-14, 15-21, 22-28, and >28 days post-vaccination. Poisson regression was used to calculate incidence rate ratios (IRR) relative to the first 7-day post-vaccination period. Results We included 199,219 individuals with 6,521,124 person-days of follow-up. SARS-CoV-2 infection was confirmed in 1,877 (0.9%), of which 489 (26.1%) were asymptomatic and 123 (6.6%) required oxygen support. The median time from the first vaccination to SARS-CoV-2 confirmation was 11.9 days (IQR 7.7-18.2). Compared with the first 7-day post-vaccination period, SARS-CoV-2 infections were lower by 65.8-84.7% during days 15-21, days 22-28, and >28 days (P <0.001 for each). For severe COVID-19, the incidence rates were 75.7-93.3% lower (P <0.001 for each) during the corresponding time periods. Conclusion Our results are consistent with an early protective effect of BNT162b2 against all degrees of SARS-CoV-2 severity.