https://apnews.com/05a7aaf7f6ef2f1e5fd52b9278422625

NEW YORK — Pfizer has started testing its potential COVID-19 treatment as a preventive medicine aimed at warding off the virus if a close contact gets it.

The drugmaker said Monday that it will study the pill it is developing in combination with a low dose of the HIV drug ritonavir in people who are at least 18 years old and live in the same household with someone who is infected.