Timing Is Everything for Merck’s COVID Pill

Two years into the pandemic, we’ve gotten a lot better at tackling the coronavirus at the extremes of infection. We have preventives—including masks, distancing, ventilation, and our MVP vaccines—that can be deployed in advance of a viral encounter. We have regimens of last resort: drugs, such as dexamethasone, that do their best, lifesaving work in hospitals with trained health-care workers, in patients whose disease has already turned severe. But in the chasm that sits in between—the hazy period after infection and before severe illness—decent tools that can derail COVID’s progression have been sparse.

We now have a new candidate aiming to fill that crucial niche: the experimental antiviral molnupiravir, developed by Merck and Ridgeback, which comes in an easy-to-swallow pill. According to a posted this past Friday, the drug can halve rates of hospitalization among people recently diagnosed with mild or moderate COVID-19. Molnupiravir hasn’t yet been given emergency clearance by the FDA, and won’t be available for at least a few months, but Merck and outside experts