As the coronavirus becomes a stubborn and unpredictable facet of everyday life, scientists and federal health officials are converging on a new strategy to immunize Americans: a vaccination campaign this fall, perhaps with doses adjusted to combat the expected version of the virus. be in circulation.
The plan would build heavily on the playbook for distributing annual flu shots and may become the blueprint for arming Americans against the coronavirus for years to come.
But some experts question how well a new vaccination push would be received by a pandemic-weary public, whether doses can be rolled out quickly enough to reach the people who need them most, and whether most Americans need extra shots.
On June 28, scientific advisers from the Food and Drug Administration (FDA) will meet to identify the variant of the coronavirus that is most likely to seep into the United States as temperatures drop. That should give manufacturers time to decide whether they need to review the composition of vaccines and ramp up production, hopefully enough to produce hundreds of millions of doses by October.
The FDA’s scientific advisers have said they would prefer to switch to a new version of the vaccines only if there is convincing evidence that the current ones are no longer effective and a modified version proves to be better.
The idea is that eligible Americans would be urged to get their coronavirus and flu shots at the same time this fall and in the same places: pharmacies, doctors’ offices, walk-in clinics and the like. Important details, such as who would be eligible, will be worked out next month at meetings of scientific advisers from the FDA and the Centers for Disease Control and Prevention.
The plan would mark a departure from current sequential authorizations of booster shots for various age groups. But the shortcomings of the annual approach have been apparent to flu researchers for years.
Scientists and federal health officials typically decide on flu vaccine formulation in the spring, six months before flu season. They guess which version of the flu virus will reach the United States by looking at what’s already circulating in the southern hemisphere, among other factors.
But in a few years, “by the time the vaccine is made, the strains have changed, and you may not have a good match,” said Dr. Ofer Levy, director of the precision vaccine program at Boston Children’s Hospital and an adviser. from the FDA. the said.
Among the candidates for a fall Covid vaccine is a booster designed for Omicron, the strange new avatar of the coronavirus, and combinations that include it. Moderna’s lead booster candidate contains 25 micrograms each of its original vaccines and one tailored to Omicron, said Dr. Paul Burton, the company’s chief medical officer.
Pfizer is also testing an Omicron-specific vaccine but won’t make a decision on its fall candidate until June, according to Jerica Pitts, a company spokeswoman.
Even if the vaccine match isn’t perfect, the boost in immunity should offer some protection against any new variants in the fall, like the flu shot does.
The number of Americans who have chosen to receive booster doses has decreased with each new recommended injection. While 90 percent of American adults have received at least one dose of a Covid vaccine, 76 percent opted for a second dose and only 50 percent opted for a third.
“Considering additional doses for a smaller and smaller return gives the impression that we don’t have a very effective vaccination program,” said Dr. Matthew Daley, a Kaiser Permanente Colorado principal investigator who leads the CDC’s vaccine task force.
A national campaign for another vaccination would unnecessarily strain pharmacists, providers and public health staff, Dr. Daley and other advisers warned at a meeting of their committee last month.
And experts worry that the push for additional doses this fall, when the risks of severe illness and death are likely to be low for most Americans, could reduce the collective willingness to get vaccinated later if a new variant emerges and the public urgently requires that.
Repeated immunizations can even blunt the effectiveness of a vaccine. For example, people who get a flu shot in a single year develop stronger immunity than those who get vaccinated two years in a row, noted Florian Krammer, an immunologist at the Icahn School of Medicine at Mount Sinai in New York.
Despite the misgivings, federal officials are preparing for a fall campaign. Combining the Covid vaccine with the flu each year is the easiest way to convince Americans to line up for vaccines, said Peter Marks, director of the FDA’s Center for Biological Evaluation and Research.
“It saves people time,” said Dr. Marks. “And it may mean more people getting both vaccines, which would be good.”
Agency scientists are actively discussing the best composition for a fall vaccine with the World Health Organization, the National Institutes of Health and vaccine manufacturers, Dr. Marks said.
The FDA is in favor of offering roughly the same formulations of the Pfizer-BioNTech and Moderna vaccines to avoid confusing people. Otherwise, “I am concerned that it could stall a vaccine campaign, when the most important thing is that people get a boost,” said Dr. Marks.
However, if the flu shot is any indication, many Americans will forgo another Covid shot. The Omicron variant has made it clear that preventing all infections is an unattainable goal, with many considered to be at low risk of serious illness or death.
Still, Dr. Marks noted that flu campaigns are also aimed at preventing lost productivity, not just medical consequences.
Before the arrival of the Omicron variant, administration officials said that Covid vaccines were intended to prevent all symptomatic infections, but they have since backtracked on that stance.
While Covid vaccines mitigated the spread of earlier variants by as much as 70 percent, “that’s clearly not true with Omicron,” he said. “It would be nice to have something that did a better job.”
Some experts said that rather than another round of injections, the best candidate for limiting infections would have been a nasal spray that coats the nose and throat with antibodies to block the virus right at its entrance. But those sprays won’t be available in the United States for at least two or three years.
Until Omicron came along, FDA scientists were so enthusiastic about mRNA vaccines that they didn’t consider alternative boosters, Dr. Marks added: “We may have been temporarily blinded by light.”
Still, minimizing the number of infections wherever possible is “obviously a very, very important secondary goal,” said Dr. Sara Oliver, who represents the CDC on the Covid-19 vaccine task force.
In addition to reducing the spread of the virus and social disruption, reducing infections should reduce cases of prolonged Covid, the constellation of symptoms that can linger for months, he said.
The new plan may revive some long-standing tensions. Disagreements over who should recommend vaccines and for whom have roiled these agencies for months.
Generally, the FDA’s scientific advisers review the safety and effectiveness of vaccines and recommend their authorization or approval. The experts who advise the CDC then issue guidelines on who should get the shots and when.
During the pandemic, the lines between the White House, the FDA and the CDC have often blurred. “Right now, one of the challenges is that we have many voices speaking on immunization policy, and historically we’ve only had one voice,” said Dr. Daley.
When the FDA authorized a second booster, for example, it did so only for adults over 50, a distinction that would normally have come from the CDC’s vaccine advisers.
The CDC also made a subtle distinction that many Americans didn’t understand: It recommended that adults over 50 could get a booster if they wanted to, not that they should. But the White House’s new Covid czar, Dr. Ashish Jha, backed second booster shots.
“It’s not entirely clear that the White House is in a position to make vaccine recommendations per se, but it did say it recommended it nonetheless,” said Dr. Camille Kotton, an infectious disease physician at Massachusetts General Hospital and scientific adviser to the CDC, said of Dr. Jha.
It is unclear who would pay for a fall vaccination campaign. The impasse in Congress over funding for Covid-19 jeopardizes the government’s ability to purchase and provide vaccines to the people who need them most.
“Without urgent additional funding, we cannot secure enough booster shots for every American who wants one if they are needed in the fall, and we cannot secure newer, more effective vaccines that protect against new variants,” Sarah Lovenheim, assistant. Secretary of Public Affairs of the Department of Health and Human Services, said.