New data from the Food and Drug Administration suggests that Johnson & Johnson’s single-dose vaccine protects against COVID-19, setting the stage for a final decision on a new and easier-to-use shot to help tame the pandemic.

A third shot on the horizon would go a long way toward vaccinating the U.S. population.

What You Need To Know

  • The FDA released data suggesting that Johnson & Johnson’s single-dose vaccine is safe and effective against COVID-19

  • The vaccine is about 66% effective at preventing moderate to severe COVID-19

  • Johnson & Johnson told Congress this week that it expected to provide 20 million doses by the end of March and 100 million by June

  • On Friday, the FDA's panel of independent advisers will meet to review the vaccine and vote on whether or not to recommend it for emergency use authorization

The FDA's scientists confirmed that overall the vaccine is about 66% effective at preventing moderate to severe COVID-19. The agency also said J&J's shot – one that could help speed vaccinations by requiring just one dose instead of two – is safe to use.

That’s just one step in the FDA’s evaluation of a third vaccine option for the U.S. The Food and Drug Administration's Vaccines and Related Biological Products Advisory Committee will meet Friday to review and vote on whether or not to recommend Johnson & Johnson's COVID-19 vaccine, signaling that a third inoculation against the deadly coronavirus could be on the horizon.

White House senior coronavirus adviser Andy Slavitt celebrated the news from the FDA on Twitter.

At a White House COVID-19 response team briefing on Wednesday, Slavitt noted that if approved, Johnson & Johnson will be able to distribute doses "without delay," with 3-4 million doses ready to be allocated next week.

Slavitt previously told governors 2 million, but some of the extra doses will be utilized for the pharmacy program.

The Johnson & Johnson contract guarantees 100 million doses by the end of June, but Slavitt noted the company is working to "accelerate" production.

The vaccination drive has been slower than hoped, hampered by logistical issues and weather delays even as the country mourns more than 500,000 virus-related deaths. So far, about 65 million Americans have received at least one dose of vaccine made by Pfizer or Moderna, shots that require two doses several weeks apart for full protection.

J&J tested its single-dose option in 44,000 people in the U.S., Latin America and South Africa. Because different mutated versions of the virus are circulating in different countries, researchers analyzed the results geographically. J&J previously announced the vaccine worked better in the U.S. – 72% effective against moderate to severe COVID-19, compared with 66% in Latin America and 57% in South Africa.

Still, in every country it was highly effective against the most serious symptoms, and early study results showed no hospitalizations or deaths starting 28 days after vaccination.

While the overall effectiveness numbers may suggest the J&J candidate isn't quite as strong as two-dose competitors, all of the world’s COVID-19 vaccines have been tested differently, making comparisons nearly impossible. While it wouldn’t be surprising if one dose turns out to be a little weaker than two doses, policymakers will decide if that’s an acceptable trade-off to get more people vaccinated faster.

Johnson & Johnson was on track to become the world's first one-dose option until earlier this month, Mexico announced it would use a one-dose version from China's CanSino. That vaccine is made with similar technology as J&J's but initially was developed as a two-dose option until beginning a one-dose test in the fall.

The rival Pfizer and Moderna vaccines being used in the U.S. and numerous other countries must be kept frozen, while the J&J shot can last three months in the refrigerator, making it easier to handle. AstraZeneca's vaccine, widely used in Europe, Britain and Israel, is made similarly and also requires refrigeration but takes two doses.

If the FDA clears the Johnson & Johnson shot for U.S. use, it won’t boost vaccine supplies significantly right away. Only a few million doses are expected to be ready for shipping in the first week. But Johnson & Johnson told Congress this week that it expected to provide 20 million doses by the end of March and 100 million by June.

European regulators and the World Health Organization also are considering Johnson & Johnson's vaccine. Worldwide, the company aims to be producing around a billion doses by the end of the year.

The Associated Press contributed to this report.