The Food and Drug Administration (FDA) on Wednesday authorized booster shots of Pfizer's COVID-19 vaccine for people aged 65 and older as well as for certain others at high risk of severe disease.
The agency said boosters are authorized for people between the ages of 18 and 64 who are at high risk as well as for those "whose frequent institutional or occupational exposure" to the virus puts them at high risk of serious complications of COVID-19.
The FDA said booster doses are to be administered at least six months after completion of the second shot.
"Today’s action demonstrates that science and the currently available data continue to guide the FDA’s decision-making for COVID-19 vaccines during this pandemic," acting FDA Commissioner Janet Woodcock said in a statement.
She added that people who would be considered at high risk include health care workers, teachers and day care staff, grocery workers, and people living in congregate facilities such as group homes and prisons.
Pfizer Chairman and Chief Executive Officer Albert Bourla in a statement said the FDA's authorization was a "critical milestone" in fighting the pandemic.
"We believe boosters have an important role to play in addressing the continued threat of this disease, alongside efforts to increase global access and uptake among the unvaccinated," he said.
The authorization aligns with the recommendations from an FDA advisory committee that on Friday overwhelmingly rejected a plan to distribute the extra shots to Americans 16 and older, which the Biden administration had been pushing for.
Instead, the panel unanimously endorsed an alternate plan to give boosters to older Americans and those at a high risk of suffering from severe illness.
The panel did not define what high risk meant, and the FDA's interpretation encompasses a wide swath of the population.
"The FDA considered the committee’s input and conducted its own thorough review of the submitted data to reach today’s decision," said Peter Marks, who directs the FDA's vaccine division. "We will continue to analyze data submitted to the FDA pertaining to the use of booster doses of COVID-19 vaccines and we will make further decisions as appropriate based on the data."
The FDA's announcement late Wednesday came relatively late in the decisionmaking process, as a Centers for Disease Control and Prevention (CDC) advisory panel had already concluded the first day of its two-day meeting about boosters.
The CDC panel is scheduled to meet Thursday to vote on the details of booster distribution, which will likely include a specific definition of high risk. Once the panel votes, its recommendation is likely to be adopted quickly by CDC Director Rochelle WalenskyRochelle WalenskyFDA greenlights mix-and-match booster doses Fauci says trick-or-treating this Halloween ok Overnight Health Care — Presented by EMAA — Pfizer requests FDA authorize COVID-19 vaccine for 5 to 11 year olds MORE. The shots could be available in pharmacies as early as this week.
Now that the FDA has decided on its interpretation of the recommendation, the CDC panel can use it to guide its own decision.
The CDC's advisory panel on Wednesday grappled with many of the same issues that complicated the FDA meeting, another sign that the Biden administration's plan to widely distribute boosters beginning this week is much more complicated than health officials anticipated.
In an unusual move last month, President BidenJoe Biden White House: US has donated 200 million COVID-19 vaccines around the world Police recommend charges against four over Sinema bathroom protest K Street revenues boom MORE and top health officials, including Woodcock, Walensky and Surgeon General Vivek MurthyVivek MurthyOvernight Health Care — Presented by Carequest — Boosters take a big step forward White House readying campaign for parents on children COVID-19 vaccines White House details plans for vaccinating children ages 5 to 11 MORE, publicly announced a booster shot program for all three vaccines would begin the week of Sept. 20, well before the FDA and CDC examined the evidence.
While officials have been careful to say the booster program is contingent on the FDA and CDC giving the green light, the move was criticized by scientists inside and outside the government.
CDC panel members on Wednesday seemed unsure that there was enough evidence that showed an extra dose of Pfizer's vaccine was necessary for the vast majority of the population. Even the possibility of distributing boosters to health workers or the elderly was unclear.
Research in the U.S. indicates that immune response does wane over time, but the current COVID-19 vaccines still afford protection against severe COVID-19 disease and death. In addition, nobody yet knows what the minimum level of antibodies is before someone's risk of infection dramatically increases.
Even if CDC endorses a targeted booster policy, there are concerns it could spark widespread confusion among the public.
People who received Moderna's vaccine and the Johnson & Johnson vaccine will not be eligible until the FDA gives those companies the green light. Moderna submitted booster data at the beginning of September, and Johnson & Johnson has not yet submitted evidence, though the company said trial and real-world evidence showed strong protection.
An FDA official told the CDC panel Wednesday the agency does not have any data on the safety or efficacy of giving a Pfizer dose to someone who received a different vaccine.
People with severely weakened immune systems are already eligible for a third dose of both the Pfizer-BioNTech and Moderna vaccines, though the broader booster recommendation will apply only to the vaccine from Pfizer-BioNTech.
Still, millions of people have already received a third dose, as pharmacies do not require a prescription or a letter from a patient's doctor for a third shot. More than 2.3 million people have received an additional dose since an extra shot was authorized last month, according to the CDC.
Updated at 8:11 p.m.