BackgroundThe role of Nirmatrelvir plus ritonavir (NMV-r) in preventing post-acute sequelae of SARS-CoV-2 infection (PASC) is unknown. The objective of this study is to assess the effect of NMV-r in non-hospitalized, vaccinated patients on the occurrence of PASC.MethodsWe performed a comparative retrospective cohort study utilizing data from the TriNetX research network, including vaccinated patients ≥18 years old who subsequently developed Covid-19 between December 2021-April 2022. Cohorts were based on NMV-r administration within five days of diagnosis. Based on previously validated broad and narrow definitions, the main outcome was the presence of symptoms associated with PASC. Outcomes were assessed between 30-180 days and 90-180 days after the index Covid-19 infection.Results1,004 patients remained in each cohort after propensity-score matching. PASC (broad definition) occurred in 425 patients (42%) in the NMV-r cohort, vs. 480 patients (48%) in the control cohort (OR 0.8 CI 0.67-0.96; p=0.01) from 30-180 days and in 273 patients (27%) in the NMV-r cohort, as compared to 347 patients (35%) in the control cohort (OR 0.707, CI 0.59-0.86; pConclusionsNMV-r treatment in non-hospitalized vaccinated patients with Covid-19 was associated with a reduction in the development of symptoms commonly observed with PASC and healthcare utilization.Key PointsAssessment of Nirmatrelvir plus ritonavir (NMV-r) in preventing post-acute sequelae of SARS-CoV-2 infection (PASC), based on broad and narrow definitions in non-hospitalized, vaccinated patients between 30-180 days and 90-180 days.