The FDA is considering new pills that could treat people in early stages of COVID. Here's what to know about how they work, how effective they are and the impact they could make on the pandemic.

"The U.K. is now the first country in the world to approve an antiviral that can be taken at home for COVID-19," Health and Social Care Secretary Sajid Javid said.

The drug, known as molnupiravir, has shown promise in treating the disease. The agreement to license its production could help millions of people in the developing world gain access to it.

Merck traditionally has been a leader in vaccines but has not had success with a COVID-19 vaccine. It's lending a hand to Johnson & Johnson, where production is running significantly behind schedule.

A 15-minute call with J&J executives on a Sunday afternoon stretched into a 75-minute turning point. "We have to take bold action and overwhelm this," a senior official said.

Merck, which previously made an Ebola vaccine, had been seen as a serious contender in the worldwide race to come up with an answer to the coronavirus.