The CDC’s Advisory Committee on Immunization Practices (ACIP) voted Thursday to unanimously recommend a booster dose of Pfizer’s COVID-19 vaccine (Comirnaty) for adults ages 65 and up and those in long-term care facilities, as well as for adults ages 50 to 64 with high-risk medical conditions (by a vote of 13-2), but that was where their agreement ended.

ACIP voted 9-6 that adults ages 18 to 49 with high-risk medical conditions should receive a booster dose of the COVID-19 vaccine based on their individual benefit and risk (which was formerly known as a “permissive” recommendation).

However, the committee voted 6-9 not to adopt an interim recommendation for adults ages 18 to 64 who were at high risk of occupational or institutional exposure to COVID-19, based on their individual benefit and risk.

Those who voted “no” argued that there was no scientific evidence to support the fact that people were at higher risk of severe COVID-19 based on their profession. Public health officials were also vehemently opposed, given the programmatic challenges involved in implementing a recommendation where people would judge their individual benefit and risk that was not based on any clinical factors.

“I just think it’s so open-ended in the way that it’s stated,” said Sarah Long, MD, of Drexel University College of Medicine in Philadelphia, who voted no. “It’s an extremely slippery slope that’s extremely difficult to interpret. I think it’s unusual for us to do, letting individuals decide vaccine policy.”

Long also said that the ACIP would be expanding on the FDA “approval,” as the point of booster doses would be to prevent severe disease, and the occupational exposure group was not one that was at increased risk of severe COVID.

Pablo Sanchez, MD, of Nationwide Children’s Hospital, who also voted no, added that an effective vaccine exists and to recommend boosters for such a broad group of people would be “like saying [the vaccine] is not working when it’s working.”

“We might as well say just give it to everybody 18 and older,” he said.

Wilbur Chen, MD, of the University of Maryland, also brought up that this could exacerbate the equity issue, that “basically people with great health literacy will get boosters” when that might not be who needs it most.

Liaison member, Jason Goldman, MD, of the American College of Physicians, said that boosters in this group were “a solution looking for a problem” and that they would “create more confusion on the provider implementation level.”

ACIP chair Grace Lee, MD, of Stanford University, who voted yes, shared a personal anecdote about caring for children who died from COVID, when they got it from a family member who was asymptomatic.

“I do worry that by inhibiting access to this, some individuals and families may suffer,” she said.

Helen Keipp Talbot, MD, of Vanderbilt University, who also voted yes, emphasized that vaccinating healthcare workers, who are being exposed in the community, would help to maintain staffing levels at already overwhelmed hospitals.

“There are caveats and groups that might not be the best fit for this recommendation, but I think healthcare workers are critical,” she said.

The rest of the votes were relatively straightforward, with the “no” votes to the third question (18 to 49 with high-risk medical condition) mainly centered on the lack of data for individuals with underlying conditions in the younger age groups, where boosters were estimated to avert fewer hospitalizations and severe cases compared to older adults.

Matthew Daley, MD, of Kaiser Permanente Colorado, who voted no, emphasized that there was a lot more “uncertainty” in the younger age groups, as well, and “the primary [vaccine] series is providing good effectiveness.”

Ultimately, the 13-2 vote for adults ages 50 to 64 was driven in part by the committee recognizing that different races and ethnicities age differently. Oliver Brooks, MD, of Watts Healthcare Corporation in Los Angeles, pointed out that African Americans were at higher risk for severe COVID beginning at age 50, not 65, although “likely a lot of that is related to underlying medical conditions,” he said.

The vote on adults ages 65 and up and those in long-term care facilities was also straightforward, as the data showed that this group derived the most benefit from boosters in terms of preventing hospitalization and death.

Mixing and matching vaccine doses also provoked discussion, with committee members upset that this booster recommendation would only apply to those who received the Pfizer vaccine as their primary series.

Peter Marks, MD, PhD, director of FDA’s Center for Biologics Evaluation and Research, said that they understood the urgency of trying to have a solution for anyone who’s been vaccinated with an authorized or approved vaccines.

“We will proceed with all due urgency to try to get there as quickly as possible … to make a science-based decision so we have something that is based on evidence to bring forward,” he said.

CDC staff noted that while these were the decisions of the ACIP today, they could be revisited as new data come in.