On Jan. 10, 2023, the U.S. National Institutes of Health (NIH) reported that antiviral treatments can help reduce the risk of serious illness and death from SARS-CoV-2, the virus that causes COVID-19. This is particularly true for those who are not fully vaccinated.

Researchers from Brigham & Women’s Hospital examined medical records from almost 45,000 people diagnosed with COVID-19. The study covered people seen during the first six months of 2022. During this time, a mix of Omicron variants was circulating in the U.S.

The team searched their hospital system’s medical records for people aged 50 and older who received a new diagnosis of COVID-19 during the time studied. They excluded people who had medical conditions that make Paxlovid unsafe. The researchers identified about 12,500 people who received a prescription for Paxlovid and just over 32,000 who did not. They used mathematical techniques to account for potential differences between the groups. These included vaccination status, age, medical history, access to health care, and other factors that could influence how patients fared.

Overall, the rates of hospitalization and death from COVID-19 were low, less than 1%, during the period studied. However, people who received Paxlovid still had a 44% reduced risk of hospitalization or death from COVID-19. People who weren’t vaccinated had an 81% lower risk of hospitalization or death if they received Paxlovid. The study results were published in the Annals of Internal Medicine.