A panel of US health advisers backed a new COVID-19 pill in a 13-10 vote on Tuesday. If the drug is authorized, this will be the first treatment for the virus Americans can use at home.

The panel's recommendation is not binding and the United States Food and Drug Administration (FDA) and is expected to make its own decision by the end of the year.

The Molnupiravir drug is already authorized for use in the UK.

What the FDA said about Molnupiravir

The FDA panel voted that the antiviral drug's benefits outweigh the risks, including potential birth defects if used during pregnancy.

The recommendation came after hours of debate about the drug's modest benefits and potential safety issues. Experts backing the treatment called on the FDA to recommend extra precautions before using the drug, including pregnancy tests for women of child-bearing age.

The vote specifically backed use of the drug by adults with mild-to-moderate COVID-19 symptoms and who face the greatest risks. This includes older people and people with conditions like obesity and asthma.

How does the drug work?

Merck’s drug molnupiravir, developed with Ridgeback Biotherapeutics, inserts tiny errors into the virus’s genetic code to stop it from reducing. This has sparked concerns that the drug could spur the virus to mutate into more virulent strains.

The drug targets part of the virus known as RNA polymerase, which has not changed much in the omicron variant.

"The [RNA polymerase] sequence of the omicron variant is not very different," said Merck scientist Daria Hazuda. "You would predict that it should be equally active."

Pfizer Inc has submitted a rival pill, Paxlovid, which has not raised concerns linked to viral mutation. It is a protease inhibitor, a family of drugs that includes pills used in standard HIV and hepatitis C treatment. The drug showed an 89% reduction in hospitalizations and deaths in its clinical trial and could be considered by the FDA in the following months.

The US government has a contract to buy as many as 5 million courses of Merck’s molnupiravir at a price of $700 per course. In comparison, the US paid around $20 per dose for its supply of the BioNTech-Pfizer vaccine.

sdi/rt (AP, AFP, Reuters)