CDC's Advisory Committee on Immunization Practices (ACIP) on Thursday unanimously voted to recommend booster shots for recipients of Moderna's and Johnson & Johnson's (J&J) Covid-19 vaccines—a recommendation that CDC Director Rochelle Walensky adopted on Thursday evening.

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Details on ACIP's recommendation

ACIP recommended that all recipients of J&J's vaccine receive a booster shot at least two months after their first dose. Those who initially received an mRNA vaccine and are eligible for boosters, including adults over the age of 65, adults ages 50 to 65 with certain medical conditions, and those who live in long-term care facilities, should receive an additional dose six months or more after their first, ACIP concluded.

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In addition, adults ages 18 to 49 with certain medical conditions and those whose jobs put them at increased risk of exposure to the coronavirus may elect to get a booster shot after considering their own individual risk, ACIP said.

Committee members raise concerns about the 'worried well'

Although the committee ultimately recommended boosters for many individuals, some members expressed concerns that the recommendation might lead the "worried well" to get extra shots they don't need, MedPage Today reports.

Sarah Long from Drexel University said the loose definition of who is eligible for booster shots is "smoke and mirrors and underhanded and winks and nods."

Long added that there's no evidence healthy people under the age of 50 need a booster shot. "I can't say I am comfortable that anyone under 50, otherwise healthy, needs a booster at this time," Long said.

Other panel members noted that, while side effects of the vaccines are uncommon, the potential for side effects may outweigh the benefits of a booster dose in younger people.

"Those that are not at high risk should really be thoughtful about getting that dose," said Helen Talbot, an infectious disease expert at Vanderbilt University.

Even so, some panel members said they felt compelled to recommend booster shots since boosters were already recommended for recipients of the Pfizer-BioNTech vaccine.

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"There are probably many people who are going to get a Moderna booster who don't need it. However, given the situation that we’ve already approved a Pfizer [booster] and there are enough people who are looking for a booster, I am inclined, reluctantly, to just go ahead and recommend a similar pattern for the Moderna booster," said James Loehr, a family physician in New York.

In the meeting, Talbot also asked Doran Fink, FDA's liaison to ACIP, whether the agency could—rather than treating a second shot of the J&J vaccine as a "booster"—instead treat it as the second dose of a two-dose regimen.

Fink said that wasn't possible, saying that "[a]t this time," J&J's vaccine is a single-dose vaccine. However, Fink added, "This is not determinative of what the vaccination regimen might ultimately be as we accrue additional data."

CDC approves ACIP's recommendations

Walensky on Thursday evening adopted ACIP's recommendations, saying they "are another example of our fundamental commitment to protect as many people as possible from Covid-19."

The Covid-19 vaccines "are all highly effective in reducing the risk of severe disease, hospitalizations, and death, even in the midst of the widely circulating delta variant," Walensky added.

CDC will later issue clinical guidance to health care providers delivering vaccines and to those who are getting booster shots. According to STAT News, that guidance will likely recommend people receive a booster shot of the same brand as their initial vaccine, but will acknowledge that may not always be possible or that some individuals may prefer to receive a different brand. (Mandavilli, New York Times, 10/22; Branswell, STAT News, 10/21; Fernandez, Axios, 10/21; Walker, MedPage Today, 10/21; Neergaard/Stobbe, Associated Press, 10/22; Schwartz, Wall Street Journal, 10/21; Gardner, Politico, 10/21)