The FDA issued the emergency clearance allowing booster shots for people older than 65 as well as people aged 18-64 who are at high risk of severe COVID-19 and who face frequent institutional or occupational exposure to COVID-19.
"After considering the totality of the available scientific evidence and the deliberations of our advisory committee of independent external experts, the FDA amended the [emergency use authorization] for the Pfizer-BioNTech COVID-19 vaccine to allow for a booster dose in certain populations such as healthcare workers, teachers and daycare staff, grocery workers and those in homeless shelters or prisons, among others," Acting FDA Commissioner Dr. Janet Woodcock said.
The agency added the booster dose should be administered six months after the standard two-dose regimen.
On Friday, the FDA's Vaccines and Related Biological Products Advisory Committee voted unanimously to recommend a third dose along similar guidelines.
"The FDA considered the committee's input and conducted its own thorough review of the submitted data to reach today's decision," Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, said in a statement. "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 Vaccines and Related Biological Products Advisory Committee's vote Friday derailed the Biden administration's plans to begin offering booster shots to nearly everyone this week.
Last week, a group of FDA scientists said a third dose of Pfizer's vaccine likely increases antibodies in recipients and offers greater protection against COVID-19. However, they stopped short of saying the extra dose is needed by a majority of Americans. They said even with waning immunity over time, the two-shot regime of the Pfizer vaccine still largely protects against severe cases of COVID-19.
A Centers for Disease Control and Prevention Advisory Committee on Immunization Practices committee also met Wednesday to consider the recommendation of a third dose.
The advisory panel was expected to discuss the issue over the course of 10 hours Wednesday.
Following Wednesday's approval, the CDC and its advisers must still provide detailed recommendations on who should receive the booster shots before they are made available.