A recent study has raised doubts about the effectiveness of Paxlovid, an antiviral medication used to treat COVID-19, particularly in vaccinated older adults. Researchers from UCLA, led by Dr. John Mafi, analyzed Canadian data and found that Paxlovid did not significantly reduce hospitalization or death rates among this demographic.
Published in JAMA on February 20, the study examined nearly 1.5 million people, focusing on those around age 70 who were eligible for Paxlovid under a Canadian health policy. The findings showed no substantial difference in outcomes between those who took the drug and those who did not. “Among vaccinated older adults, Paxlovid showed no statistically significant reduction in COVID-19 hospitalizations or mortality,” said Mafi.
These results contrast sharply with Pfizer’s 2022 clinical trial, which found an 89% reduction in hospitalizations and deaths among mostly unvaccinated, middle-aged adults. Pfizer responded to the new study, stating it remains confident in Paxlovid’s effectiveness for high-risk patients.
While Paxlovid is intended for individuals at higher risk of severe illness, including the elderly and those with compromised immune systems, this study suggests that its benefits for vaccinated individuals may be smaller than previously believed. “We are not saying that Paxlovid is useless,” Mafi clarified. “Its effectiveness in vaccinated older adults is far lower than the earlier evidence from unvaccinated groups indicated.”
The researchers acknowledge some limitations in their study, including the inability to assess participants’ full vaccination histories or whether they took Paxlovid within the recommended five-day window after symptoms appeared. More detailed research is planned to address these factors.
Despite the findings, medical professionals emphasize that Paxlovid may still benefit certain high-risk individuals. Dr. Katherine Kahn, the study’s senior author, stated that she would consider prescribing Paxlovid to patients with higher risks of complications, though its benefits for generally healthy individuals remain uncertain. The study’s authors call for further research to better understand Paxlovid’s impact in today’s vaccinated population, ensuring that treatment decisions are informed by the most up-to-date evidence.
