New Pill Cuts COVID Risk 70% After Household Exposure

Living with someone who has COVID-19 just got a lot less risky, thanks to a pill that could finally prevent infection after you've been exposed.

The drug ensitrelvir slashed the risk of developing symptomatic COVID-19 by nearly 70 percent in a major clinical trial published in the New England Journal of Medicine. Among people living with someone sick with COVID-19, only 3 percent of those taking the pill got sick, compared to 9 percent who took a placebo.

The trial included nearly 2,400 people ages 12 and older across five countries, from the United States to South Africa to Vietnam. Everyone had a household member who'd recently tested positive and showed symptoms.

Half started a five-day course of ensitrelvir within 72 hours of their household contact getting sick. The other half received a placebo, and neither participants nor researchers knew who got what.

The drug works by blocking an enzyme the virus needs to replicate itself, similar to how Paxlovid treats active infections. But unlike Paxlovid, which failed to prevent infection in a previous trial, ensitrelvir succeeded.

Even among those who did catch COVID-19 while taking ensitrelvir, the virus levels in their noses and throats were much lower than in the placebo group. That suggests they were likely less contagious to others around them.

The Ripple Effect

This breakthrough could transform protection for the people who need it most. Older adults and those with weakened immune systems now have a new shield beyond vaccines and boosters.

Healthcare workers facing constant exposure could also benefit significantly. Instead of just hoping their immunity holds up, they'd have an actual intervention after a risky patient encounter.

The drug recently earned approval in Japan under the brand name Xocova for post-exposure protection. The FDA is expected to decide on U.S. approval this June.

Experts emphasize the pill complements rather than replaces vaccination. Most trial participants already had some immunity from past infection or shots, yet the drug still provided powerful additional protection.

After more than six years of living with COVID-19, we finally have a proven way to stop the virus in its tracks after exposure.