IE 11 is not supported. For an optimal experience visit our site on another browser.

FDA authorizes Pfizer and Moderna boosters for all adults

The decision comes after a number of states and cities moved on their own to recommend the shot.
Image:  Pfizer-BioNTech Covid-19 vaccine
A health care worker administers a dose of the Pfizer-BioNTech Covid-19 vaccine in Birmingham, Ala., on Aug. 28. Andi Rice / Bloomberg via Getty Images file

The Food and Drug Administration on Friday authorized Pfizer-BioNTech and Moderna's Covid-19 boosters for all adults, a move that will make boosters available to everyone ages 18 and up.

Pfizer requested authorization last week, citing results from a Phase 3 clinical trial with more than 10,000 participants that found that the third dose was safe and effective. Moderna requested authorization Wednesday.

Full coverage of the Covid-19 pandemic

“The FDA has determined that the currently available data support expanding the eligibility of a single booster dose of the Moderna and Pfizer-BioNTech Covid-19 vaccines to individuals 18 years of age and older,” Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said in a statement Friday.

The FDA did not seek the advice of its independent advisory panel, called the Vaccines and Related Biological Products Advisory Committee, when reviewing either company's data.

John Grabenstein, a former executive director of medical affairs for vaccines at Merck, as well as a former immunologist for the Defense Department, said the FDA did not need to ask its advisory committee to weigh in at this time.

“This isn’t a matter of antibody response or safety,” he said. “The FDA can make that decision on its own.”

Dr. Jesse Goodman, a professor of medicine and infectious diseases at Georgetown University Medical Center, expressed surprise that the FDA’s decision on Moderna came so quickly, just two days after the company applied for authorization.

“It is important to be sure the FDA has been able to thoroughly review data submitted by the sponsors as well as any other relevant information,” said Goodman, a former chief scientist with the FDA. “So, unless they previously received and reviewed much of Moderna’s data, if the EUA request was, as reported, made a few days ago, that could raise concerns.”

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said Tuesday that no safety signals linked to booster shots have emerged thus far, including for younger adults.

The second dose of an mRNA vaccine, from both Pfizer and Moderna, has been linked to a small but increased risk of myocarditis, or heart inflammation, particularly in young men.

"We’re in pretty close contact with our Israeli colleagues, and they say that for the people who get the third dose of an mRNA, in their case, Pfizer, they have not seen any signal that makes them feel that the risk outweighs the benefit for that group," Fauci said.

The onus now shifts to the Centers for Disease Control and Prevention, whose vaccine advisory committee is scheduled to meet Friday afternoon to hammer out the final recommendations for the shots.

Typically, CDC signoff is the final step needed before shots can be administered. In an unusual move, however, a number of states and cities chose not to wait for the FDA or the CDC to act, instead opting to allow boosters for all adults in the past week.

Covid cases continue to rise in the United States, and more than 30 percent of the country has yet to receive a single dose of the vaccine.

"The big question to me is, can we booster ourselves out of this pandemic?" said Norman Baylor, president and CEO of Biologics Consulting, a biotech consulting firm, and a former director of the FDA’s Office of Vaccines Research and Review. "Until we vaccinate those groups that have not been vaccinated, I’m not sure we can."

Download the NBC News app for full coverage of the Covid-19 pandemic

Pfizer and Moderna's booster shots are given at least six months after the completion of the initial two-dose vaccination series.

All adults who were initially vaccinated with the Johnson & Johnson vaccine are also eligible for a booster shot.

As of Thursday, more than 31 million people in the U.S. have received a booster shot, according to the CDC.

Follow NBC HEALTH on Twitter & Facebook