Currently, a second booster shot is available only to those 50 and older, as well as to those 12 and older who are immunocompromised. But administration officials are concerned by data that suggests immunity wanes within several months of the first booster shot. Swiftly expanding access to booster shots also would enable people who are boosted now to receive reformulated shots that target newer virus variants, when those become available, probably later this year. In addition, officials want to use vaccine doses that are reaching their expiration dates and would otherwise be discarded.
While the booster plan still needs formal sign-off from regulators and public health officials, it has the backing of White House coronavirus coordinator Ashish Jha and Anthony S. Fauci, the government’s top infectious-disease expert, according to five officials who like others interviewed in this report spoke on the condition of anonymity because they were not authorized to discuss the plan.
The Centers for Disease Control and Prevention recommends that all Americans age 5 and older receive at least one booster shot several months after undergoing their initial vaccinations, although the timing varies based on which vaccine was originally administered. Regulators in March also said adults over age 50 and some immunocompromised people should receive a second booster.
While about 67 percent of all Americans have been fully vaccinated against the virus, only 34 percent of eligible Americans have received a first booster dose, according to federal data.
In an interview, Fauci said he’s “leaning” toward allowing second booster shots for younger adults, pending authorization from the Food and Drug Administration and agreement by the CDC.
While persuading those who haven’t gotten vaccinated or fully vaccinated to get the full regimen and their first booster shot is critical, Fauci said, “we also need to allow people who are under 50 to get their second booster shot, since it may have been months since many of them got their first booster.”
“If I got my third shot [in 2021], it is very likely the immunity is waning,” he added.
Another official said some administration experts are worried the BA. 4 and BA. 5 subvariants of omicron “might be a little worse” than earlier virus lineages, citing the modest increase in hospitalizations and concerns the trend might worsen.
Those officials hope to move within the next two weeks to broaden eligibility to boosters and avoid having the strategy get tangled up with the administration’s planned vaccination campaign this fall. That effort is likely to kick off in October, using reformulated vaccines specifically tailored to target the omicron subvariants.
The White House referred questions to its health agencies. An FDA spokesperson said the agency is evaluating the situation, including the emerging epidemiology indicating increased hospitalizations, and will be open to all potential options to address this, if necessary. The CDC did not immediately respond to a request for comment.
CDC Director Rochelle Walensky and FDA officials have privately signaled their openness to the strategy, three officials said. “This is a really complex decision, and there are pros and cons that need to be carefully weighed,” one of the officials said.
Some outside experts have cautioned against a second booster shot for more Americans, however, saying there is scant data supporting the strategy.
Paul Offit, director of the Vaccine Education Center at the Children’s Hospital of Philadelphia and an outside adviser to the FDA, has repeatedly criticized federal officials for what he characterized as “booster mania.”
“I do think [a second booster shot] does make sense for certain groups, but a universal boosting strategy doesn’t make sense,” Offit said in an interview Monday, citing data showing that three doses of mRNA vaccine provided long-lasting protection against severe disease. “At some level, we’re going to have to get used to mild illness and moderate illness as part of this virus — which is going to be with us for the rest of my life, the rest of my children’s lives, the rest of their children’s lives.”
Offit also warned that repeatedly administering the same vaccine could lead to a phenomenon known as “imprinting,” where an individual’s immune system develops a highly targeted response to earlier versions of a virus and fails to adapt as that virus evolves.
“As you continue to boost with the same ancestral strain, you lock yourself into that response,” Offit said. “Should there ever be a virus that is truly resistant to protection against serious illness … you need to start all over again and give that vaccine.”
Other experts and officials embrace the idea of making a fourth shot more widely available.
At a recent FDA vaccine advisory committee meeting, Kent Carper, president of the Kanawha County Commission in West Virginia, pleaded with the agency for broader eligibility for second booster shots so that younger first responders could get them.
“There is an urgent need for second booster shots to protect our first responders,” Carper said. “First responders include law enforcement, firefighters, EMTs, telecommunicators, nurses and our doctors. It’s important this is done now and not later.”
Peter Hotez, a molecular virologist and dean of the National School of Tropical Medicine at Baylor College of Medicine, told The Post that he supports the authorization of a second booster shot for people younger than 50.
We have already seen the benefits in 50 and older,” he said, citing a pattern that’s emerged with earlier data. “Eventually what’s true for older people turns out to be true for younger folks — it just takes longer to reveal itself.”
According to preliminary unpublished CDC data presented to FDA’s vaccine advisory committee late last month, a fourth mRNA dose was 62 percent effective in preventing urgent care and emergency room visits among healthy adults older than 50 during omicron, when different subvariants were dominant. A fourth dose was 80 percent effective in preventing hospitalizations.
But Ruth Link-Gelles, a CDC epidemiologist who leads the agency’s task force on vaccine effectiveness, said that while a fourth dose provides “substantial additional protection” among those with frail immune systems and healthy adults over 50, it was “too early to draw conclusions” about a fourth dose in the broader population.
There is no U.S. data for people under 50, CDC officials said. An ongoing randomized clinical trial in the United Kingdom suggests a fourth dose of mRNA vaccines can boost the immune system to a similar extent as the third dose, or first booster.