Paxlovid and molnupiravir were authorized by the US FDA last week, but supplies of Paxlovid are limited while molnupiravir is less effective than hoped

An effective and widely available treatment for Covid would be a significant breakthrough for managing the pandemic, but two antivirals recently authorized in the US come with some significant caveats, including low supply and use only among those at high risk for severe illness and death.

Paxlovid from Pfizer and molnupiravir from Merck and Ridgeback Biotherapeutics were authorized by the US Food and Drug Administration (FDA) last week. The pills could be a game-changer for the most vulnerable, because they can be taken at home twice a day for five days to prevent hospitalization and death. For those considered at high risk of serious illness, Paxlovid was found to be 89% effective when taken within the first three days of symptoms and 88% effective in the first five days.