When I spoke with Fauci, he repeatedly emphasized that the point of Paxlovid is “to keep you out of the hospital and prevent you from progressing to severe disease.” But does the drug really have this benefit for young, vaccinated people, who would seem to represent a significant proportion of those taking it? COVID hospitalization rates for those younger than 60 are currently less than two per 100,000. Given those numbers, Paxlovid—or any other drug, for that matter—isn’t likely to provide much benefit. “If your risk of hospitalization is incredibly low, to make that even lower is somewhat improbable,” David Boulware, an infectious-disease physician and a researcher at the University of Minnesota, told me.

That might explain why Pfizer’s trial found no statistically significant effect on hospitalization among a group of unvaccinated people at low risk from the disease and vaccinated people at high risk. An Israeli study conducted this winter similarly showed that Paxlovid did not significantly affect hospitalization rates in vaccinated, high-risk patients younger than 65. A study from Hong Kong did find that vaccinated Paxlovid takers were only about two-thirds as likely as non-takers to be hospitalized; but these data were not broken down by age, and the most popular vaccine choice among older Hong Kongers, Sinovac, is less effective than the mRNA-based vaccines that have dominated in the United States. A study that Woolley co-authored in Massachusetts found that Paxlovid reduced the risk of hospitalization for vaccinated people of all ages by 28 percent; and if a person’s last shot was more than 20 weeks old, the protection offered by the pills nearly doubled.

With the exception of Pfizer’s clinical trial, these studies are not placebo-controlled experiments, which makes them vulnerable to confounding factors. Woolley acknowledged the limitations of her own research, and told me that the benefit she found was “incremental.” Still, thanks to the paper, “I do feel like I have, now, significant data and experience to be able to have a well-informed discussion with my patients,” she said. “I’m not worried that we are giving placebo.”