The FDA will soon decide on Merck's Covid-19 antiviral pill. It shows promise, but there are also concerns

In the fall of 2015, Dr. Mark Denison was preparing for a long drive home from Alabama after making a presentation at a scientific meeting when a colleague asked him to stick around for lunch and check out some data on a potential new drug. Denison said yes, and six years later, he's very glad he stayed. Denison's colleague, George Painter, is a 'drug hunter' at Emory University in Atlanta. At lunch, he showed Denison lab results he'd obtained with a new antiviral compound, now known as molnupiravir. 'It just knocked my socks off,' said Denison, an infectious disease specialist at Vanderbilt University Medical Center. 'With increasing concentrations of the drug, the virus's ability to grow just plummeted.' Painter's lab looked at the effect molnupiravir had against the influenza virus and chikungunya, a virus that's spread by mosquitos. After the Alabama meeting, Painter sent some of the compound to Denison, who tried it in his lab against the virus that causes Middle East Respiratory Syndrome.