Two separate antiviral pills for at-home treatment for the coronavirus were approved by the U.S. Food and Drug Administration in the days leading up to Christmas. Pfizer announced on Dec. 22 that COVID-19 pill, to be marketed as Paxlovid, had been authorized for distribution, followed a day later by a similar announcement from Merck. Merck’s pill carries the generic name molnupiravir. Both treatments will be free to patients in the U.S.

Data from Pfizer’s clinical trial showed its new drug, taken with the older antiviral drug ritonavir, is 90 percent effective in preventing hospitalizations and deaths in patients at high risk of severe illness. Recent lab data suggests the drug retains its effectiveness against omicron. The FDA authorized the oral drug for the treatment of high-risk adult patients and pediatric patients at least 12 years of age with COVID-19 outside of the hospital. The company said it was ready to start immediate delivery in the U.S. and raised its production projections to 120 million courses of treatment from 80 million in 2022.

The U.S. government’s contract for purchase of 10 million courses of the Pfizer drug is priced at $530 per course. The U.S. will pay about $700 for each course of Merck’s drug, which requires patients to take four pills twice a day for five days.

The Food and Drug Administration authorized Merck’s drug for adults with early symptoms of COVID-19 who face the highest risks of hospitalization, including older people and those with conditions like obesity and heart disease. The U.K. first authorized the pill in early November.