Abstract
ObjectiveThis study examined the initial impact of a national BNT162b2 vaccine rollout on SARS-CoV-2 infections in Qatar. MethodsAll individuals who had completed ≥14 days of follow-up by 16 March 2021 after receiving the BNT162b2 vaccine were included. This study 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. ResultsA total of 199,219 individuals with 6,521,124 person-days of follow-up were included. SARS-CoV-2 infection was confirmed in 1877 (0.9%), of which 489 (26.1%) were asymptomatic and 123 (6.6%) required oxygen support. The median time from 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 15–21, 22–28, and >28 days (P < 0.001 for each). For severe COVID-19, the incidence rates were 75.7–93.3% lower during the corresponding time periods (P < 0.001 for each). ConclusionThe results were consistent with an early protective effect of BNT162b2 vaccine against all degrees of SARS-CoV-2 severity.
Highlights
MethodsA two-dose regimen of BNT162b2, the Pfizer-BioNTech COVID19 mRNA vaccine, was shown to reduce the risk of SARS-CoV-2 by around 95% in a randomized clinical trial and in a mass national vaccination program (Dagan et al, 2021; Polack et al, 2020)
For fatal COVID-19 cases, symptoms started after a median of 12 days after the first BNT162b2 dose
In comparison with the first 7-day post-vaccination period, the incidence rate ratios (IRR) for severe COVID-19 decreased significantly during days 15–21 (IRR 0.243, 95% confidence intervals (CI) 0.136–0.434, P < 0.001), days 22–28 (IRR 0.171, 95% CI 0.087– 0.335, P < 0.001), and >28 days (IRR 0.067, 95% CI 00.028–0.161, P < 0.001) (Figure 1). These findings are consistent with those previously shown in a community setting and in healthcare workers, but this report is the first to include an entire national cohort of BNT162b2 recipients (Dagan et al, 2021; Hall et al, 2021)
Summary
MethodsA two-dose regimen of BNT162b2, the Pfizer-BioNTech COVID19 mRNA vaccine, was shown to reduce the risk of SARS-CoV-2 by around 95% in a randomized clinical trial and in a mass national vaccination program (Dagan et al, 2021; Polack et al, 2020). A two-dose regimen of BNT162b2, the Pfizer-BioNTech COVID19 mRNA vaccine, was shown to reduce the risk of SARS-CoV-2 by around 95% in a randomized clinical trial and in a mass national vaccination program (Dagan et al, 2021; Polack et al, 2020). On 23 December 2020, Qatar started a national BNT162b2 rollout programme, in addition to existing COVID-19 public health control measures.
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