In just a week, COVID-19 vaccine boosters could begin to be available to all fully vaccinated Americans. But exactly who will be eligible and when won't be decided until two key scientific advisory committees meet days before the Biden administration's Sept. 20 start date.
That leaves little reaction time for health care system administrators like Dr. Tammy Lundstrom, chief medical officer for Michigan-based Trinity Health, which operates 92 hospitals and 120 continuing care facilities in 22 states.
"We have our data team poised, ready to hit the button to help us identify all our patients who are ready for a booster," Lundstrom said. "We're anxiously waiting for guidance, as is everybody."
Originally, President Joe Biden said a third shot booster dose for people with healthy immune systems would be offered beginning Sept. 20 to anyone who'd gotten their second shot of either the Pfizer-BioNTech or Moderna vaccine at least eight months ago, pending authorization from the Food and Drug Administration.
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But the administration walked that back slightly over concerns the announcement got ahead of recommendations from the Food and Drug Administration and Centers for Disease Control and Prevention advisory committees.
"The decision of which booster shots to give, when to start them and who will give them will be left completely to the scientists at the FDA and the Centers for Disease Control," Biden said Thursday.
The FDA committee meets Friday to discuss booster recommendations; the CDC committee meeting is not yet scheduled but could come the next day to meet the Sept. 20 goal.
The Vaccines and Related Biological Products Advisory Committee is where the FDA goes for outside advice on whether the data for drugs and vaccines shows they will be safe and effective. The committee also can grill the agency on questions it feels haven't yet been answered. The CDC's Advisory Committee on Immunization Practices develops recommendations for who should get vaccines and on what schedule.
Medical systems are preparing for a down-to-the-wire decision.
"If you look back in in the history of the pandemic, most of the FDA decisions happened on a Friday and most of the CDC meetings happened on a Saturday or Sunday. So we've geared up," Lundstrom said.
What those two committees say will determine who's eligible for boosters and when, said Dr. Kelly Moore, president and chief executive officer of Immunize.org, which educates health care professionals about U.S. vaccine recommendations.
The White House initially said there would be an eight-month interval between the second and third dose, but it could be a "minimum" of six months with a "recommended" interval of eight months, Moore said.
"A lot of vaccines, including hepatitis B and the human papillomavirus, come in a three-dose series with the first two doses close together and the third at least six months after the first," she said.
The decisions will depend on the data.
"We can speculate all day long, but until we can see how these vaccines work in the real world, we don’t need to be speculating about what our public policy should be in advance," she said.
As of Aug.13, people with severely weakened immune systems, about 2.7% of the population, became eligible for a third shot after it was found they may not have gotten enough protection from the original two-dose schedule.
It's not known whether the CDC's committee will simply recommend everyone get a booster after some specific number of months or will be more specific, such as saying health care workers or the elderly should go first.
"A specific interval would be easiest to implement," Moore said.
At least initially, the only booster will be Pfizer-BioNTech's, called Comirnaty, which was the first to submit data. Moderna's application to the FDA wasn't completed until Sept. 3 and is still under review.
Supply is not expected to be a problem.
COVID-19 vaccines are plentiful and readily available in most of the United States at this point, so no one expects the availability challenges when the first vaccine doses were distributed in December and January.
It's also easier to administer the Pfizer-BioNTech vaccine because its initial ultracold storage requirements have changed. Now it can be stored in an ordinary freezer for up to two weeks and then in an ordinary refrigerator for up to a month.
Still, much depends on the recommendations for when to get a booster. Eight months ago, only about 2 million people had gotten their second dose of vaccine, almost all of them health care workers along with some seniors. Six months ago the numbers were much higher and spread across a broader swath of America.
The one thing doctors are clear on is where to add the third shot to the CDC's COVID-19 Vaccination Record Card, Lundstrom said. The first two lines on the card are labeled "1st dose COVID-19" and "2nd dose COVID-19." The last two lines are labeled "Other."
"That's where we're asking people to document the third dose," she said.
Waiting is better, experts say
Health care systems are relying on the honor system for those who come in for booster shots. No one's going to have guards checking to see who's eligible, said Rebecca Coyle, executive director of the American Immunization Registry Association. However, the public should follow the guidelines and not push to the front of the line.
"Remember, any providers administering these vaccines had to sign the provider enrollment agreement and is beholden to it," she said. "It's very clear they should not be administering these doses outside of the recommendations."
Waiting longer is the better choice medically, said vaccinologist, pharmacist and public health leader John Grabenstein.
“You want multiple months to pass by so that your immune system matures and gets ready for that next dose. If you want a really good response to Shot 3, you shouldn’t rush,” he said.
Grabenstein said he hasn't seen any data that shows people eight months out from their last shot have had significant loss of protection against severe disease, only against mild or moderate disease.
"What matters is whether people continue to be protected against severe disease, not that people are protected against mild breakthrough cases. The goal of the vaccination program is to prevent death," he said.
Having to persuade people to wait a little longer is a happy complication, Moore said.
"This is a new problem for us, having to beat people off with a stick because they want more vaccine. The conversation we're usually having is 'Please take this, it will save your life.' Now we're telling them, 'Please, not yet.'"