No significant reduction seen in risk for symptomatic SARS-CoV-2 infection with postexposure prophylaxis for five or 10 days<\/p>\n<\/h3>\n
By Elana Gotkine HealthDay Reporter<\/b><\/p>\n
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THURSDAY, July 18, 2024 (HealthDay News) — Postexposure prophylaxis with nirmatrelvir-ritonavir for five or 10 days does not reduce the risk for symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, according to a study published in the July 18 issue of the New England Journal of Medicine<\/em>.<\/p>\n Jennifer Hammond, Ph.D., from Pfizer in Collegeville, Pennsylvania, and colleagues conducted a phase 2 to 3 double-blind trial to examine the efficacy and safety of nirmatrelvir-ritonavir in asymptomatic adults who had been exposed to a household contact with COVID-19 within 96 hours before randomization and were rapid antigen test-negative for COVID-19. Participants were randomly assigned to nirmatrelvir-ritonavir every 12 hours for five days (921 participants) or for 10 days (917 participants) or to matching placebo for five or 10 days (898 participants).<\/p>\n The researchers found that symptomatic, confirmed SARS-CoV-2 infection developed by day 14 in 2.6, 2.4, and 3.9 percent of participants in the five-day nirmatrelvir-ritonavir group, the 10-day nirmatrelvir-ritonavir group, and placebo group, respectively. The percentage of participants in whom symptomatic, confirmed SARS-CoV-2 infection developed did not differ significantly for each nirmatrelvir-ritonavir group versus the placebo group, with risk reductions relative to placebo of 29.8 and 35.5 percent in the five- and 10-day nirmatrelvir-ritonavir groups, respectively. The trial groups had a similar incidence of adverse events.<\/p>\n “Among adult household contacts of symptomatic persons with confirmed COVID-19, nirmatrelvir-ritonavir given as postexposure prophylaxis for five or 10 days did not significantly reduce the risk of development of SARS-CoV-2 infection as compared with placebo,” the authors write.<\/p>\n The study was funded by Pfizer, the manufacturer of oral nirmatrelvir-ritonavir.<\/p>\n