Centers for Disease Control and Prevention advisers voted Thursday to recommend a third shot of the COVID-19 vaccine for high-risk individuals, kicking off another round of mass vaccinations.

People who are 18 or older with underlying medical problems and seniors 65 and older are eligible for a third Pfizer shot. 

The advisory committee recommended, 15-0, booster shots for people ages 65 and over and long-term care facility residents. The committee then voted, 13-2, to recommend a third shot for adults ages 50 to 64 who are at risk for severe COVID-19 due to an underlying health condition. Members voted, 9-6, for those who are 18 to 49 with underlying conditions.

The committee voted, 6-9, against recommending a third shot for adults ages 18 to 64 who are in an occupational or institutional setting that puts them at high risk for contracting COVID-19. Members plan to revisit this question in future meetings.

The vote came a day after the Food and Drug Administration authorized a third shot of the Pfizer COVID-19 vaccine for adults ages 65 and up and individuals at high risk for severe disease, such as people with underlying conditions or essential workers. The FDA authorized booster shots to go in arms six months past the date of a second dose.

The booster is only for individuals who received Pfizer as their initial series. The Pfizer COVID-19 vaccine is authorized for individuals ages 16 and up, but the booster shot is authorized only for individuals 18 and up.

Committee members unanimously agreed that people 65 and older and long-term care residents should receive a third shot, but as the votes revealed, they were less sure about recommending the extra shots for younger groups who may be at risk.

Data shows that people 65 and older receive the most benefit from a booster dose, especially when it comes to preventing severe disease from the delta variant, but the benefit for people of other ages is incrementally smaller given the high effectiveness from the primary vaccine series.

Discussion and dissent

Some members argued against the widespread use of booster shots in younger age groups. The panel decided that a third shot could provide protection to those with underlying health conditions, but an additional shot may not benefit a healthy, vaccinated person who works in a high-risk setting and wears personal protective gear.

Pablo Sanchez, a professor of pediatrics at Ohio State University, cautioned that recommending the shot to everyone ages 18 and up who works in a high-risk setting could undermine confidence in the vaccine because it could give the impression that the initial series of vaccinations was ineffective.

“We have a really effective vaccine, and it’s like saying it’s not working. And [the vaccine] is working,” Sanchez said.

Helen Talbot, a committee member and an associate professor of medicine at Vanderbilt University, said boosters would solve only part of the problem as long as large portions of the country remain unvaccinated. She also argued that Johnson & Johnson vaccine recipients are in more dire need of booster shots than Pfizer recipients because the one-shot vaccine has lower efficacy in preventing severe disease after vaccination.

“I worry we are getting distracted by the question of boosters and Pfizer when we have bigger and more important things to do during the pandemic,” Talbot said, adding, “I feel like we’re putting lipstick on frogs.”

James Loeher, an owner of Cayuga Family Medicine, argued that even if every person who received a Pfizer vaccine received a booster, it would not reduce hospitalizations by that much because the original two shots still largely protect against severe disease and death.

“I feel we have too much hope with these boosters,” Loeher said.