Researchers are studying various treatments for covid-19 outpatients, including antiviral medications such as nirmatrelvir-ritonavir. Some studies suggest these treatments can reduce hospitalization and prevent long-term covid-19 symptoms in adult outpatients, while others have found mixed results, including one trial that showed no reduction in hospitalization or death rates in vaccinated high-risk outpatients. The effectiveness of different treatments for covid-19 outpatients is being examined in multiple clinical trials and reviews.