The Food and Drug Administration on Dec. 22, 2021, granted emergency use authorization (EUA) for a new antiviral pill to treat people with symptomatic COVID-19.

Pfizer’s ritonavir, name brand Paxlovid, can now be taken by patients ages 12 and up who weigh at least 88 pounds.

The antiviral is only for people who test positive for the coronavirus and who are at high risk for severe COVID-19, including hospitalization or death. It is available by prescription only and should be taken as soon as possible after diagnosis and within 5 days of the start of symptoms.

Paxlovid is taken as three tablets together orally twice a day for 5 days, for a total of 30 tablets.

Possible side effects include a reduced sense of taste, diarrhea, high blood pressure, and muscle aches.

The authorization arrives as U.S. cases of the Omicron variant are surging, some monoclonal antibody treatments are becoming less effective, and Americans struggle to maintain some sense of tradition and normalcy around the holidays.

Paxlovid joins remdesivir as an available antiviral to treat COVID-19. Remdesivir is fully approved by the FDA but is given only intravenously in a hospital.

The COVID-19 antiviral pills come with some obvious advantages, including greater convenience for consumers – such as home use – and the potential to expand treatment for people in low- and middle-income countries.

‘An exciting step forward’

The EUA for Pfizer’s new drug has been highly anticipated, and news of its impending authorization circulated on social media on Tuesday. Eric Topol, MD, called the development an “exciting step forward.” Dr. Topol is editor in chief of Medscape, the parent company of MDedge.

He and many others also expected the FDA to grant emergency use authorization for an antiviral from Merck. But there was no immediate word Wednesday if that was still going to happen.

An accelerated authorization?

The FDA’s authorization for Pfizer’s antiviral comes about 5 weeks after the company submitted an application to the agency. In its submission, the company said a study showed the pill reduced by 89% the rate of hospitalization and death for people with mild to moderate COVID-19 illness.

In April 2021, Pfizer announced its antiviral pill for COVID-19 could be available by year’s end. In September, an official at the National Institutes of Allergy and Infectious Diseases seconded the prediction.

Merck filed its EUA application with the FDA in October. The company included results of its phase 3 study showing the treatment was linked to a 50% reduction in COVID-19 hospitalizations.

Interestingly, in September, Merck announced the findings of laboratory studies suggesting that molnupiravir would work against variants of the coronavirus because the agent does not target the virus’s spike protein. At the time, Delta was the dominant variant in the United States.

Faith-based purchasing

The U.S. government has already recognized the potential of these oral therapies, at least in terms of preorders.

Last month, it announced intentions to purchase $1 billion worth of Merck’s molnupiravir, adding to the $1.2 billion worth of the pills the U.S. ordered in June 2021. Also in November, the government announced it would purchase 10 million courses of the Pfizer pill at an estimated cost of $5.3 billion.

The government preorders of the antiviral pills for COVID-19 are separate from the orders for COVID-19 vaccines. Most recently, the Biden administration announced it will make 500 million tests for coronavirus infection available to Americans for free in early 2022.

A version of this article first appeared on WebMD.com.

FDA authorizes Pfizer antiviral pill for COVID-19