This phase 2–3, double-blind, randomized, placebo-controlled trial evaluated two nirmatrelvir–ritonavir regimens as postexposure prophylaxis for household contacts of persons with Covid-19.

Further analysis showed nirmatrelvir-ritonavir was significantly associated with reduced risk of mortality within 1 year of COVID-19 diagnosis (aHR, 0.37; 95% CI, 0.21-0.65; P <.01), with similar ...