A key adviser to the Food and Drug Administration's vaccine panel is questioning whether more Covid booster shots are necessary for healthy, younger people.
The evidence for the new versions of the vaccines for the omicron variant of the coronavirus, which the FDA authorized in August, is "underwhelming" and fails to show they are much better than the original shots, Dr. Paul Offit, a pediatrician who is a leading vaccine and infectious diseases expert, wrote Wednesday in the New England Journal of Medicine.
Protecting people against Covid infection with the current mRNA technology may be a pipe dream, especially as new coronavirus strains emerge every few months, Offit, the director of the Vaccine Education Center at Children's Hospital of Philadelphia, told NBC News.
The updated boosters from Pfizer-BioNTech and Moderna are probably best reserved for people at high risk of severe illness or death from Covid — older adults, people with multiple coexisting conditions and those who are immunocompromised, Offit said.
Asking young, healthy people who have a lower risk of serious illness to get boosted with a variant-specific vaccine, followed by a different variant-specific formula a few months later, may not be practical, he said.
Offit, who is a member of the FDA’s Vaccine and Related Biological Products Advisory Committee, wrote in the paper, “I believe we should stop trying to prevent all symptomatic infections in healthy, young people by boosting them with vaccines containing mRNA from strains that might disappear a few months later.”
The FDA vaccine committee is scheduled to meet Jan. 26, when the group of outside advisers will hammer out what the next version of Covid shots should be.
Offit's position contradicts Covid vaccine guidelines from the FDA and the Centers for Disease Control and Prevention, which recommend that everyone 6 months and older get updated vaccines at least two months after their last doses.
In response to the NEJM paper, FDA spokesperson Abigail Capobianco said that the data Offit used to support his argument was “selective” and that “we strongly believe that the totality of the available evidence continues to support the use of these vaccines in all age groups.”
“Dr. Offit is entitled to his opinion about the effectiveness of the Covid-19 bivalent vaccines used as boosters,” she said.
Why is there an omicron booster?
In the wake of last winter's surge of the omicron variant in the U.S., the FDA's vaccine committee met in June to recommend redesigned boosters that target some form of the omicron virus. Offit and another member voted against changing the vaccines. The FDA later backed the vaccine panel, authorizing a new formulation of the booster shots.
The updated vaccine, called a bivalent, targets the original coronavirus strain as well as BA.4 and BA.5, two omicron subvariants that are now largely out of circulation in the U.S.
At the time, the updated booster shots hadn't yet been tested in humans, and early data suggested that they didn't generate a better immune response to BA.5 than the first iterations of the vaccines.
However, data released in the following months by Pfizer and Moderna, as well as a real-world study from the CDC, found that the new vaccines did offer increased protection against the omicron subvariants, although the protection against infection was still low compared to the protection they once offered against the original coronavirus strain.
Dr. Peter Hotez, a co-director of the Center for Vaccine Development at Texas Children’s Hospital, countered that the boosters still lower the risk of Covid infections and severe illness — and in turn lower the risk of getting long Covid.
“The people who are talking about why young people need it are missing the point,” he said, referring to the booster. “We don’t only vaccinate to prevent deaths. We prevent vaccine severe illness and therefore long Covid, as well.”
It's unclear whether the new paper will influence other members of the FDA panel or the agency's decision about the next version of the vaccines.
Dr. Ofer Levy, another member of the FDA panel, agreed that the benefit of a booster may be lower for younger people than for older adults but said, "It is not zero."
Levy, the director of the Precision Vaccines Program at Boston Children’s Hospital, continues to encourage Covid boosters for everyone who is eligible.
Relatively few people in the U.S. have had updated boosters. As of Jan. 4, only around 15% of people over age 5 had gotten them, according to the CDC.
Dr. Anna Durbin, a vaccine researcher at Johns Hopkins University in Baltimore, said the rationale for boosting young, healthy people is "weaker" than it is for boosting the elderly and those at higher risk for severe disease. However, she said, young people are still likely to get infected.
The FDA advisory committee is expected this month to discuss whether the first two mRNA vaccine doses given to people who aren't yet vaccinated should be updated to match the current circulating strains of the virus. Those shots, called the primary series, still target the original coronavirus strain that was identified in Wuhan, China, in late 2019.