Centers for Disease Control and Prevention Director Rochelle Walensky, MD, has officially signed off on a recommendation by an independent panel of 11 experts to allow people with weakened immune function to get a third dose of certain COVID-19 vaccines.
The decision follows a unanimous vote by the CDC’s Advisory Committee on Immunization Practices (ACIP), which in turn came hours after the U.S. Food and Drug Administration updated its Emergency Use Authorization (EUA) for the Pfizer and Moderna mRNA vaccines.
About 7 million adults in the United States have moderately to severely impaired immune function because of a medical condition they live with or a medication they take to manage a health condition.
People who fall into this category are at higher risk of being hospitalized or dying if they get COVID-19. They are also more likely to transmit the infection. About 40% of vaccinated patients who are hospitalized with breakthrough cases are immunocompromised.
Recent studies have shown that between one-third and one-half of immunocompromised people who didn’t develop antibodies after two doses of a vaccine do get some level of protection after a third dose.
Even then, however, the protection immunocompromised people get from vaccines is not as robust as someone who has healthy immune function, and some panel members were concerned that a third dose might come with a false sense of security.
“My only concern with adding a third dose for the immunocompromised is the impression that our immunocompromised population [will] then be safe,” said ACIP member Helen Talbot, MD, MPH, an associate professor of medicine at Vanderbilt University Medical Center in Nashville, Tenn.
“I think the reality is they’ll be safer but still at incredibly high risk for severe disease and death,” she said.
In updating its EUA, the FDA stressed that, even after a third dose, people who are immunocompromised will still need to wear a mask indoors, socially distance, and avoid large crowds. In addition, family members and other close contacts should be fully vaccinated to protect these vulnerable individuals.
Johnson & Johnson not in the mix
The boosters will be available to children as young as 12 years of age who’ve had a Pfizer vaccine or those ages 18 and older who’ve gotten the Moderna vaccine.
For now, people who’ve had the one-dose Johnson & Johnson vaccine have not been cleared to get a second dose of any vaccine.
FDA experts acknowledged the gap but said that people who had received the Johnson & Johnson vaccine represented a small slice of vaccinated Americans, and said they couldn’t act before the FDA had updated its authorization for that vaccine, which the agency is actively exploring.
“We had to do what we’re doing based on the data we have in hand,” said Peter Marks, MD, director of the Center for Biologics Evaluation and Research at the FDA, the division of the agency that regulates vaccines.
“We think at least there is a solution here for the very large majority of immunocompromised individuals, and we believe we will probably have a solution for the remainder in the not-too-distant future,” Dr. Marks said.
In its updated EUA, the FDA said that the third shots were intended for people who had undergone solid organ transplants or have an “equivalent level of immunocompromise.”