In a presentation to the committee members, Daria Hazuda, a Merck executive, said molnupiravir’s activity is similar across known variants and that the drug works in a way that makes it likely to be active against new variants.

Another Merck executive, Dr. Nicholas Kartsonis, told the panel on Tuesday that the company is “feverishly working” to collect samples from people infected with Omicron that it can use in laboratory studies to help determine whether the drug will work against the variant…

In a clinical trial, molnupiravir was found to reduce by 30 percent the risk of hospitalization or death when given to high-risk, unvaccinated volunteers within five days after they started showing symptoms. It appears to be substantially less effective than Pfizer’s pill, which was found to lower risk by 89 percent, and monoclonal antibody treatments, which have been found to cut it by at least 70 percent.