Merck’s antiviral drug for COVID-19, molnupiravir, which is currently under review of the US Food and Drug Administration for marketing authorisation, seems less effective than suggested by results that came out from its early clinical trials. According to an analysis by scientists at the FDA, this experimental drug reduced the risk of hospitalization or death from COVID-19 only by about 30 percent compared to a placebo. The FDA analysis also found that the drug showed zero benefit for people with antibodies against COVID-19 from prior infection. The FDA review showed 48 hospitalisations or deaths among study participants who were randomly assigned to take the antiviral drug, compared to 68 among those who took a placebo. These results came from a set of 1,433 patients who were randomized in the clinical trial. On the contrary, the results from the first 775 patients enrolled in the clinical trial, announced  by the inventor earlier, claimed the drug reduced the risk of hospitalization or death for patients at high risk of severe disease by about 50 percent.