Johnson & Johnson’s 1-dose COVID-19 vaccine approved for emergency use, FDA says

Johnson & Johnson’s one-dose COVID-19 vaccine was approved for emergency use by the U.S. Food and Drug Administration Saturday.

The one-dose vaccine could start rolling out in the U.S. as early as Monday to combat severe illness caused by the COVID-19 virus.

"This is exciting news for all Americans, and an encouraging development in our efforts to bring an end to the crisis," President Joe Biden said in a statement. 

The approval comes just one day after an FDA panel of U.S. health advisers endorsed the vaccine, and as new supplies are urgently needed to stay ahead of a mutating virus that has killed more than 500,000 Americans.

RELATED: Johnson & Johnson's single-shot COVID-19 vaccine endorsed by FDA expert panel 

After daylong discussions, the FDA panelists voted unanimously on Friday that the benefits of the vaccine outweighed the risks for adults. 

More than 47 million people in the U.S., or 14% of the population, have received at least one shot of the two-dose vaccines from Pfizer and Moderna, which FDA authorized in December. But the pace of vaccinations has been strained by limited supplies and delays due to winter storms.

J&J’s vaccine protects against the worst effects of COVID-19 after one shot, and it can be stored up to three months at refrigerator temperatures, making it easier to handle than the previous vaccines, which must be frozen.

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While early J&J supplies will be small, the company has said it can deliver 20 million doses by the end of March and a total of 100 million by the end of June.

Projected deliveries from Pfizer, Moderna and J&J combine for 240 million doses slated for late March, and 700 million jabs by mid-year, the latter of which is more than enough to vaccinate the U.S. population.

Jeff Zients, White House COVID-19 coordinator, said the U.S. is averaging 1.4 million doses of vaccine administered per day, down from last week's average of 1.7 million. Data compiled by the U.S. Centers for Disease Control and Prevention says over 22.6 million Americans have received two doses, meaning 6.8% of the country's population is fully vaccinated.

RELATED: Vaccine 'passports' may open society, but inequity looms

On Thursday, Biden marked the administration of the 50 millionth dose of COVID-19 vaccine since his swearing-in. The moment came days ahead of a meeting with the nation's governors on plans to speed the distribution even further.

"The more people get vaccinated, the faster we’re going to beat this pandemic," Biden said at the White House ceremony, noting that his administration is on course to exceed his promise to deliver 100 million shots in his first 100 days in office.

"We’re halfway there: 50 million shots in 37 days," Biden said. "That’s weeks ahead of schedule."

RELATED: Pfizer researching effects of 3rd COVID-19 vaccine dose

On Sunday, a CDC panel is expected to meet to recommend how to best prioritize use of the J&J vaccine.

Other parts of the world already are facing which-is-best challenges. Italy’s main teachers’ union recently protested when the government decided to reserve Pfizer and Moderna shots for the elderly and designate AstraZeneca’s vaccine for younger, at-risk workers. AstraZeneca’s vaccine was deemed to be about 70% effective in testing. Canada became the latest country Friday to allow use of AstraZeneca’s vaccine.

The number of people hospitalized with COVID-19 in the U.S. has dropped by 80,000 in six weeks since the start of mass vaccine rollouts but despite this slightly more positive result, deaths are still persistently high, though much lower than the peak in early January, when they sometimes exceeded 4,000 per day.

The novel coronavirus is responsible for the deaths of more than 510,000 Americans as of Feb. 27, 2021, with more than 28 million cases having been reported nationwide, according to data from Johns Hopkins.