What to Know About the New COVID-19 Vaccine Booster

In a long-awaited update to the COVID-19 vaccine schedule, the U.S. Centers for Disease Control (CDC)’s vaccine committee recommended that everyone six months or older should get another booster shot.

CDC director Dr. Mandy Cohen endorsed the recommendation made by the agency’s committee of outside vaccine experts.

That shot will be the newest vaccine greenlit by the Food and Drug Administration (FDA) just a day earlier. The FDA approved mRNA vaccines made by Moderna and Pfizer-BioNTech that target the XBB.1.5 variant for everyone 12 years or older, and issued an emergency use authorization for mRNA vaccines for children six months to 11 years. The FDA’s actions also mean that the updated vaccine is the only one authorized or approved against COVID-19; the previous booster, against BA.4/5 is no longer authorized.

In a 13-1 vote, the CDC’s panel of vaccine experts decided that near-universal vaccination for everyone six months or older would provide the best protection against another serious surge in infections this fall and winter. Hospitalizations due to COVID-19 have been increasing since mid-July, CDC scientists reported, and while most of those have involved young children and older people, half of the children under five who have been hospitalized did not have underlying health conditions, a reminder that even otherwise healthy people can experience serious COVID-19 illness.

Despite the near unanimous vote in favor of recommending the vaccine for most people, committee members raised several concerns. First, the new vaccines target the XBB.1.5 variant—which is no longer the virus causing the most infections in the U.S., but was the dominant virus earlier in the summer, when the FDA made the decision to switch to a new vaccine. At the time, the agency advised manufacturers to start producing shots targeting that variant. But XBB.1.5 has since been replaced by a handful of new strains, including EG.5.1 and BA.2.86. Moderna, Pfizer, and Novavax all presented data to the committee showing that their XBB-targeted vaccines generated good antibody responses against these new variants as well, but only Moderna’s data involved human cells while Pfizer and Novavax provided data from animal studies. (Novavax has not yet submitted a request to the FDA to authorize its XBB vaccine, but expects to do so soon when its studies are complete.)

Some members  questioned whether the updated vaccine should be recommended for most people, or just for those at highest risk of COVID-19 complications, such as the very young, the elderly, and those with compromised immune systems. Dr. Matt Daley, senior investigator at the Institute for Health Research at Kaiser Permanente Colorado, and the head of the CDC’s work group that reviewed the vaccine safety and effectiveness data, said that when the group began discussions earlier this summer, they did not assume that the updated vaccine would be recommended for everyone. “We viewed this as an opportunity to re-evaluate the vaccination program, and started from a blank slate,” he said. The work group therefore asked the CDC for more detailed data on who was being hospitalized, who was experiencing more severe disease, and who was dying from COVID-19, so it could better understand if certain populations were more vulnerable to complications and could benefit from vaccination. What they saw was that “Disease burden does vary greatly by age, but serious illness occurred across all age groups including among those without underlying medical conditions,” Daley said. “That was the most persuasive argument for me for universal vaccination.”

Those data, coupled with the fact that many people did not get the most recent booster, means that overall immunity against SARS-CoV-2 is dropping, said Dr. Sandra Fryhoffer, associate professor of medicine at Emory University who was representing the American Medical Association at the meeting. “We are all more susceptible.”

Most of the committee members agreed, but Dr. Pablo Sanchez, professor of pediatrics at Ohio State University-Nationwide Children’s Hospital, was the only member to vote against the recommendation. “I think we need to let the public know that the data on children is not there,” said Sanchez. “We need to level with our patients and say what is known and what is unknown rather than make a blanket recommendation, especially for groups for whom there isn’t data.” Sanchez argued for a recommendation that focused on the most vulnerable groups, such as people over 65 years, the immunocompromised, and pregnant people, and encouraged other groups to make individual decisions about getting vaccinated after discussing their risks and benefits with their doctors.

Some committee members shared Sanchez’s concerns about the lack of data, but also pointed out that without a universal recommendation, current inequities in vaccine access would only deepen since those without access to health care would not benefit from individual discussions about their need for a vaccine.

The updated vaccine will be the first COVID-19 shot to be distributed in the way most vaccines have in the past, prior to the pandemic, on the commercial market for around $120-$130 per dose, rather than purchased and provided for by the government. That means that pharmacies and doctors’ offices will purchase the vaccines at their own cost and get reimbursed for the shots. Most insurers, including Medicare and private companies, will continue to cover the vaccine, without co-pays, since it is recommended by the CDC. 

The Vaccines for Children program will provide shots for uninsured and underinsured younger kids. For older children and adults without adequate insurance coverage, the CDC announced that it will purchase shots and make them available at state and local health departments, as well as through retail pharmacies that participate in the Bridge Access Program until 2024. To sustain the program beyond that for adults, the agency hopes to secure additional funding to launch a permanent Vaccines for Adults program and extend the shots it provides beyond COVID-19 vaccines.