BNT162b2 post-exposure-prophylaxis against COVID-19

Background During the COVID-19 pandemic, post-exposure-prophylaxis is not a practice. Following exposure, only patient isolation is imposed. Moreover, no therapeutic prevention approach is applied. We asked whether evidence exists for reduced mortality rate following post-exposure-prophylaxis. Methods To estimate the effectiveness of post-exposure-prophylaxis, we obtained data from the Israeli Ministry of Health (MoH) registry. The study population consisted of Israeli residents aged 12 years and older, identified for the first time as PCR-positive for SARS-CoV-2, between December 20 th , 2020 (the beginning of the vaccination campaign) and October 7 th , 2021. We compared “recently injected” patients - that proved PCR-positive on the same day or on one of the five consecutive days after first vaccination (representing an unintended post-exposure-prophylaxis), to unvaccinated control group. Results Among Israeli residents identified PCR-positive for SARS-CoV-2, 11,690 were found positive on the day they received their first vaccine injection (BNT162b2) or on one of the 5 days thereafter. In patients over 65 years, 143 deaths occurred among 1413 recently injected (10.12%) compared to 280 deaths among the 1413 unvaccinated (19.82%), odd ratio (OR) 0.46 (95% confidence interval (CI), 0.36 to 0.57; P<0.001). The most significant reduction in the death toll was observed among the 55 to 64 age group, with 8 deaths occurring among the 1322 recently injected (0.61%) compared to 43 deaths among the 1322 unvaccinated control (3.25%), OR 0.18 (95% CI, 0.07 to 0.39; P<0.001). Conclusion Post-exposure-prophylaxis is effective against death in COVID-19 infection. Israeli MoH Registry Number HMO-0372-20