03052nam a2200277   4500001000800000005001700008007000300025008004100028040000800069041000800077100002600085245007600111300002500187520222800212650001602440650001702456650003902473650002402512700002402536700002302560700002602583700001802609700002402627700002002651773010302671ESSALUD20260902160450.0ta      t        pe ||||| |||| 00| 0 spa d  aBMG  aeng  aHayden, Frederick G.   aEnsitrelvir for Covid-19 postexposure prophylaxis in household contacts  apáginas: 1905-1915  aBackground: Ensitrelvir, an oral inhibitor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 3C-like protease, is approved in Japan for the treatment of mild-to-moderate coronavirus disease 2019 (Covid-19). Previously, no antiviral agents were approved for postexposure prophylaxis in household contacts of patients with Covid-19. Methods: In this double-blind, randomized, placebo-controlled trial, we randomly assigned persons who were SARS-CoV-2–negative on local diagnostic testing but were household contacts of a patient with Covid-19 (the index patient) to receive either ensitrelvir (375 mg on day 1 and 125 mg daily on days 2 through 5) or placebo within 72 hours after symptom onset in the index patient. The primary end point was Covid-19 (defined by a central laboratory–confirmed positive reverse-transcriptase–polymerase-chain-reaction assay and the presence of ≥1 of 14 prespecified Covid-19 symptoms lasting ≥48 hours) by day 10 in a household contact in the modified intention-to-treat population (all the participants who underwent randomization, had a central laboratory–confirmed negative RT-PCR test for SARS-CoV-2 at baseline, and received at least one dose of the trial drug or placebo). Results: The modified intention-to-treat population included 1030 participants in the ensitrelvir group and 1011 in the placebo group. The mean age of the participants was 42.4 years; 71.1% had undergone randomization within 48 hours after symptom onset in the index patient, and 37.0% had at least one risk factor for severe Covid-19. The incidence of Covid-19 was lower in the ensitrelvir group than in the placebo group (2.9% vs. 9.0%; risk ratio, 0.33; 95% confidence interval [CI], 0.22 to 0.49; P<0.001). The incidence of adverse events during the trial was similar in the two groups (15.1% in the ensitrelvir group and 15.5% in the placebo group), as was the incidence of serious adverse events (0.2% in each group). No Covid-19–related hospitalizations or deaths were reported. Conclusions: Ensitrelvir administered to household contacts of a patient with Covid-19 within 72 hours after symptom onset in the index patient was effective in preventing Covid-19 in the contacts.   aCORONAVIRUS  aSALUD GLOBAL  aENFERMEDADES INFECCIOSAS GENERALES  aINFECCIONES VIRALES  aShinkai, Masaharu    aClark, Tristan W.   aLuetkemeyer, Anne F.   aSax, Paul E.   aHanage, William P.   aGebo, Kelly A. 0 022717dMassachusetts NEJM GroupoNEJM014tThe New England Journal of Medicine wESSALUDx0028-4793