Johnson & Johnson's COVID-19 vaccine scores FDA authorization, adding key third shot to U.S. supply

A month after Johnson & Johnson's COVID-19 vaccine posted positive data in a phase 3 study, the shot is ready for prime time. After a key FDA panel unanimously endorsed the vaccine late Friday, the agency signed off on its emergency use Saturday.

The FDA's authorization for the one-dose vaccine provides a quick lift for the U.S. immunization effort at an important time. J&J has said it expects to have 4 million doses ready to ship at the time of authorization, plus a total of 20 million doses by the end of March and 100 million doses by mid-year. 

On Friday, the Vaccines and Related Biological Products Advisory Committee voted in favor of the vaccine after a daylong public hearing on its efficacy data, its safety profile, COVID-19 variants, post-marketing safety tracking and more. In the end, the panelists decided the vaccine's benefits outweighed its risks in people 18 and older. Over the weekend, the agency issued the emergency use authorization and the CDC supported its use.

As the first vaccine considered since two important variants were discovered—and lab tests showed existing vaccines may be less potent against them—J&J's shot faced questions during its FDA committee review that vaccines from Pfizer and Moderna did not.

For instance, committee member Steven Pergam asked J&J’s scientists about the need for vaccines tailored to variants. J&J’s Johan Van Hoof, M.D., global therapeutic area head of infectious disease and vaccines, said the vaccine showed efficacy that is “quite high” against severe disease from the South African variant. Plus, efficacy against that variant seems to improve over time against moderate and severe disease, Van Hoof said. 

It’s still not known “whether there is a new generation vaccine needed,” Van Hoof said, but J&J is working on an updated vaccine that should enter early human testing before the summer. The company is "not complacent," he said, and continues to monitor how the situation is evolving. 

RELATED: J&J single shot sees 66% efficacy in moderate COVID-19, 85% in severe cases; shares fall 

In a massive late-stage study, J&J's vaccine posted 66% efficacy against severe disease in all countries and 72% in the U.S. In addition, the vaccine offered “complete protection” against COVID-19 related hospitalizations and death at 28 days after vaccination, the company said.  

About a week after J&J released findings from the study, the company submitted its program to the FDA for an emergency authorization, and the regulator set up Friday’s hearing with independent vaccine experts. Days ahead of the hearing, FDA staffers offered their endorsement of the vaccine. 

J&J will now add a third coronavirus vaccine to the United States’ high-stakes immunization rollout. Since the Pfizer and Moderna vaccines won FDA authorizations in December, officials have distributed 91.7 million doses, and 61.3 million of those have been administered. As worrisome variants spread, experts say it's critical to vaccinate as many people as possible as quickly as possible.

RELATED: Pfizer, Moderna and J&J tout supercharged COVID-19 vaccine output, eyeing nearly 140M doses by March 

Overall COVID-19 vaccine availability is expected to ramp up significantly this month. Pfizer, Moderna and J&J execs recently told Congress the companies should have a combined 140 million new doses ready for distribution in March. 

Other vaccine authorizations could follow for the vaccines from AstraZeneca and Novavax. Both are running late-stage studies that could enable the companies to submit FDA applications in the weeks and months to come. 

Editor's note: This story was updated Monday following the FDA's emergency use authorization for J&J's vaccine.