(The Hill) – An advisory group for the Food and Drug Administration (FDA) has voted to recommend Merck’s COVID-19 antiviral pill for infected adults at high risk for severe coronavirus illness, hospitalization or death.

The panel narrowly endorsed Merck’s five-day oral treatment in a 13-10 vote on Tuesday.

The advisers recommended the FDA authorize the pill, developed with Ridgeback Biotherapeutics, for adult patients enduring mild-to-moderate COVID-19 who face a higher risk of serious illness, including due to underlying health conditions.

Approval of these pills could expand accessibility with at-home COVID-19 treatments, pending FDA authorization and Centers for Disease Control and Prevention (CDC) approval. The U.S. has already agreed to buy 3.1 million courses of the drug, with the option to purchase more.

Antiviral COVID-19 drugs have been considered a potential game changer in the pandemic, since all current drugs require an injection or IV. Other pills are in development, including Paxlovid from Pfizer, which requested FDA authorization earlier this month. 

The vote comes after the FDA released its review of Merck’s data on the drug last week that concluded molnupiravir’s effectiveness but raised concerns about its effects on pregnant people. 

Merck representatives recommended during the meeting that people who are pregnant or breastfeeding do not take the pills due to potential risks, including possible toxicity and birth defects. 

The pharmaceutical company suggested women at childbearing age use contraception while receiving molnupiravir. Merck plans to launch a pregnancy surveillance program to further track the drug’s effects on pregnant people. 

Merck is also not currently seeking authorization for the pill to be administered to children.

Some experts expressed worries that the drug, which inserts small errors into the virus’s genetic code to prevent replication, could spark the virus to mutate into more dangerous strains, although the FDA considers the issue a “theoretical” concern.

The drug manufacturer filed for an emergency use authorization last month after its study suggested molnupiravir reduced the risk of hospitalization by 50 percent. But updated data from Friday showed a 30 percent reduction in hospitalizations among more participants. 

Merck’s pill would not function as a preventative treatment as it would be administered to already infected individuals to avoid worse outcomes. 

The treatment is not designed to replace vaccinations as COVID-19 vaccines would still be needed to stop infection in the first place. Merck did not study the drug’s effects among vaccinated people. 

The advisers’ decision also comes as anxiety has mounted over the World Health Organization’s most recent variant of concern: the omicron strain.

A Merck representative told the FDA in the meeting that the company has not tested molnupiravir against the omicron variant, but they expect the pill to remain effective against the strain.