The Food and Drug Administration on Saturday issued an emergency authorization for a Covid-19 vaccine developed by Johnson & Johnson, the third vaccine to be cleared for use in the United States and the first that requires only one dose.
The vaccine, which has not yet been tested in children or adolescents, was cleared for use in adults aged 18 and older.
The addition of J&J’s vaccine to the arsenal could offer a distinct advantage in the effort to vaccinate large swaths of the American public as quickly as possible. The single-shot vaccine doesn’t have the same onerous cold-chain requirements as the two vaccines developed by Moderna and the Pfizer/BioNTech partnership.
“The authorization of this vaccine expands the availability of vaccines, the best medical prevention method for COVID-19, to help us in the fight against this pandemic, which has claimed over half a million lives in the United States,” Janet Woodcock, acting commissioner of the FDA, said in a statement.
The federal government has purchased 100 million doses of the J&J vaccine, but supplies are expected to be scarce until at least April. In a call with reporters late Saturday, Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said vaccine would be shipped “as early as next week” and that an “increasing number of doses will be available over the coming months,” but declined to provide specific details.
The FDA’s decision came after an outside panel of experts unanimously recommended on Friday that regulators authorize the vaccine, which was developed by J&J’s vaccine division Janssen Pharmaceuticals. The shot was found to reduce cases of moderate to severe Covid infection by 66.1%, starting 28 days after the single shot. Results from a multi-country study, released in late January, suggested the vaccine worked better in some regions of the world than others. In the U.S., the vaccine was 72% protective.
An FDA analysis of the J&J data suggested the vaccine was slightly less effective against a virus variant first spotted in South Africa, known as B.1.351. Another variant, known as P.2., didn’t appear to erode the vaccine’s protection.
J&J is also conducting a trial in the United States of a two-dose vaccine, with the doses given eight weeks apart. The results from that 30,000-person trial are not expected until sometime in May. During Friday’s meeting of the expert panel, several members questioned whether that trial will show that the J&J vaccine really should be given in a two-dose regimen. But Marion Gruber, director of the FDA’s Office of Vaccines Research and Review, suggested if the results point to a second dose being needed, that can be addressed when J&J files for full licensure of its vaccine.
The approval for all adults comes despite the fact that the data on elderly adults from the company’s Phase 3 study were limited. Some of J&J’s data also raised questions about how well the vaccine works in adults 60 and older who have comorbidities, or underlying medical conditions. The committee ultimately voted unanimously to recommend the vaccine be used in those 18 or older, without any restrictions on age.
FDA reviewers were confident that the differences in effectiveness for people older than 60 who have comorbidities may dissipate with more data, Marks said.
“Obviously we will watch that watch as additional data come in, but at this time there is no concern about reduced efficacy in the older population,” Marks said.
Moderna’s vaccine is also authorized for use in those 18 and older, while the Pfizer/BioNTech vaccine can be given to those 16 and older. J&J plans to launch a trial in adolescents soon, and has also said it plans to study the shot’s safety and efficacy in people who are immunocompromised in the third quarter of this year.
Common side effects of vaccination in the study included injection site pain, fatigue, and muscle aches. While unexpected side effects occurred at the same rate in the vaccine and placebo groups — about 0.5% — some rare conditions appeared more frequently in participants who received the vaccine. Blood clot-related issues appeared in 15 volunteers who received the vaccine, compared to 10 in the placebo group. The FDA has said it would recommend monitoring for such events after an EUA is granted.
The CDC has also been monitoring cases of anaphylaxis, a severe and potentially life-threatening allergic reaction, in the vaccine rollout. There have been a small number of cases reported after receipt of both the Pfizer and the Moderna vaccines. Macaya Douoguih, head of clinical development and medical affairs for Janssen, told the advisory panel on Friday that one participant in an open-label study in South Africa developed anaphylaxis after receiving the vaccine. Prior to that, there had been no reported cases of anaphylaxis in the company’s studies.
There are several other vaccines still being tested that have not yet been authorized in the U.S., including candidates from AstraZeneca and Novavax.
This story has been updated with additional comment from FDA officials.