After more than a year and a half of an agonizing pandemic, researchers at Merck and Ridgeback Biotherapeutics have announced a successful oral antiviral treatment. The drug, called molnupiravir, prevents about half of COVID-19-associated hospitalizations. The data monitoring committee, which oversees clinical trials, stopped the trials because the evidence of efficacy was sufficiently persuasive — hospitalizations reduced by 50%, deaths by 100% — that they deemed it unethical to continue with a placebo-treated control group.

On Oct. 11, the sponsors requested emergency use authorization from the Food and Drug Administration. Merck expects to have more than 10 million courses of therapy available by the end of this year.