UPDATE: An advisory panel to the Centers for Disease Control and Prevention on Thursday recommended extra doses for people 65 and older, nursing home residents, and people who are 50 to 64 with underlying medical conditions. It also said boosters can be offered to people 18 to 49 with underlying conditions. Latest developments here.
Who could be eligible for a COVID vaccine booster shot and when?
The FDA on Wednesday authorized booster doses for Americans who are 65 and older, younger adults with underlying health conditions and those in jobs that put them at high risk for COVID-19. The ruling represents a drastically scaled back version of the Biden administration’s sweeping plan to give third doses to nearly all American adults to shore up their protection amid the spread of the highly contagious delta variant.
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But more regulatory hurdles lie ahead before the dispensing of boosters can begin.
Scientists inside and outside the government have been divided in recent days over the need for boosters and who should get them.
Here's what we know so far:
Can I get a booster shot now?
The U.S. has so far only approved Pfizer and Moderna boosters for certain people with weakened immune systems, such as cancer patients and transplant recipients.
While the FDA authorized booster doses of Pfizer's COVID-19 vaccine for Americans who are 65 and older, younger adults with underlying health conditions and those in jobs that put them at high risk for COVID, advisers to the Centers for Disease Control and Prevention opened a two-day meeting Wednesday to make their own, more specific recommendations about who should get the extra shots and when.
For now, several million Americans who are especially vulnerable because of organ transplants, certain cancers or other disorders and who received the Moderna or Pfizer COVID vaccines can get a booster shot of those vaccines.
According to the CDC, the list includes people who have:
- Been receiving active cancer treatment for tumors or cancers of the blood
- Received an organ transplant and are taking medicine to suppress the immune system
- Received a stem cell transplant within the last 2 years or are taking medicine to suppress the immune system
- Moderate or severe primary immunodeficiency (such as DiGeorge syndrome, Wiskott-Aldrich syndrome)
- Advanced or untreated HIV infection
- Active treatment with high-dose corticosteroids or other drugs that may suppress your immune response
The agency notes that "people should talk to their healthcare provider about their medical condition, and whether getting an additional dose is appropriate for them."
When might I be able to get a booster shot?
Despite the resistance in recent days, some top U.S. health officials said they expect boosters to eventually win broader approval in the coming weeks or months. Dr. Anthony Fauci said over the weekend that “this is not the end of the story.”
FDA acting commissioner Dr. Janet Woodcock said in a statement that the FDA authorization would allow for boosters of the Pfizer vaccine in health care workers, teachers, grocery workers and those in homeless shelters or prisons.
But advisers to the Centers for Disease Control and Prevention will recommend who should get one. And in their first day of discussions, some experts were so perplexed by the questions surrounding the rationale for boosters that they suggested putting off a decision for a month in hopes of more evidence.
Under the FDA authorization, vaccinated Americans are eligible for a third dose six months after receiving their second Pfizer shot.
Chicago's top doctor anticipates a decision by the end of the week, she said Tuesday.
"The way this works is that the FDA is looking at the safety in the production and gives the sort of green light, in terms of, 'Yes, a vaccine or a medication is authorized to be used,' but the CDC are the ones who actually give the specific recommendations of who and how," Chicago Department of Public Health Commissioner Dr. Allison Arwady said during a Facebook Live Tuesday.
U.S. regulators are expected decide at a later date on boosters for people who have received the Moderna or Johnson & Johnson vaccines. They indicated the Pfizer shots would not be recommended for people who got a different brand of vaccine initially.
What about those who got Moderna or Johnson & Johnson vaccines?
U.S. regulators will decide at a later date on boosters for people who have received the Moderna or Johnson & Johnson vaccines. They indicated the Pfizer shots would not be recommended for people who got a different brand of vaccine initially.
Adding to the complexity, Moderna wants its booster to be half the dose of the original shots.
Moderna previously released data on breakthrough cases, saying it supports the push for wide use of COVID-19 vaccine booster shots.
But as the FDA's Vaccines and Related Biological Products Advisory Committee debated administering third doses of Pfizer and BioNTech's vaccine, federal health regulators said they needed more time to review Moderna's application for extra doses.
Johnson & Johnson on Tuesday released data showing that a booster dose to its one-shot coronavirus vaccine provides a strong immune response months after people receive a first dose.
J&J said in statement Tuesday that it ran two early studies in people previously given its vaccine and found that a second dose produced an increased antibody response in adults from age 18 to 55. The study's results haven't yet been peer-reviewed.
The company is in talks with regulators including the U.S. Food and Drug Administration, the European Medicines Agency and others regarding using booster doses of its vaccine.
Health officials have said they were expecting to receive more data in the fall and will "keep the public informed with a timely plan for J&J booster shots as well."
The FDA and CDC’s approval and recommendation for immunocompromised individuals does not apply to those who got the Johnson & Johnson vaccine.
If I got the Moderna or J&J vaccine should I get a booster shot of the Pfizer vaccine?
Federal experts have indicated the Pfizer shots would not be recommended for people who got a different brand of vaccine initially.
Chicago's top doctor has also said the answer to that question is likely no, but further information is expected when the CDC advisers announce their decision.
"If I had gotten the Moderna vaccine, I would not personally - I would not go and get a Pfizer booster," she said. "Right now, our biggest priority is the people who are not even vaccinated at all, in terms of dropping the risk for everybody - even people who are vaccinated, continuing to keep the focus on people getting their first and second doses of vaccine is the most important thing. But my expectation is for people over 65, you'll be able to get boosters through the pharmacies, through your doctor's office through, you know, the clinics or regular immunization clinics, all of the above. So expect a more formal update and recommendations probably at the very end of this week."
For those who received the Moderna or Pfizer vaccine, the CDC says "a third dose of the same mRNA vaccine should be used."
"A person should not receive more than three mRNA vaccine doses. If the mRNA vaccine product given for the first two doses is not available or is unknown, either mRNA COVID-19 vaccine product may be administered," the agency's website states.
When can eligible people get their third dose?
The FDA determined that transplant recipients and others with a similar level of compromised immunity can receive a third dose of the vaccines from Pfizer and Moderna at least 28 days after getting their second shot.
Walgreens announced last month that its pharmacies will offer additional COVID-19 vaccine doses to eligible patients with compromised immune systems.
Walgreens has begun offering same-day appointments available to such patients on a walk-in basis at select stores, the company said. Patients will bring their vaccination card or record to the appointments to prove eligibility.
Under the recent FDA authorization for seniors and high-risk populations, eligible vaccinated Americans would be able to receive their third dose six months after receiving their second Pfizer shot.
Are there any risks with getting a booster shot? What about side effects?
The CDC reports there is "limited information about the risks of receiving an additional dose of vaccine, and the safety, efficacy, and benefit of additional doses of COVID-19 vaccine in immunocompromised people continues to be evaluated."
The agency noted that side effects with the third shot "were similar to that of the two-dose series."
The most common symptoms include fatigue and pain at the injection site, but "most symptoms were mild to moderate."
As with previous doses of the vaccine, the CDC notes that, "serious side effects are rare, but may occur."
Will booster shots contain the original vaccine, or one tailored to delta?
The boosters will be an extra dose of the original vaccine. Manufacturers still are studying experimental doses tweaked to better match delta. There’s no public data yet that it’s time to make such a dramatic switch, which would take more time to roll out. And independent research, including studies from Ellebedy’s team, shows the original vaccine produces antibodies that can target delta.
“I’m very, very confident that this vaccine will work against delta with a single booster of the same vaccine,” Pfizer CEO Albert Bourla told The Associated Press.
How much protection will I get?
No one yet knows “the magic line” — the antibody level known as the correlate of protection below which people are at risk for even mild infection, said immunologist Ali Ellebedy of Washington University at St. Louis.
But vaccines’ main purpose is to prevent severe disease. “It’s a very high bar to really go and say we can completely block infection,” Ellebedy noted.
Plus, people’s responses to their initial vaccination vary. Younger people, for example, tend to produce more antibodies to begin with than older adults. That means months later when antibody levels have naturally declined, some people may still have enough to fend off infection while others don’t.
That initial variation is behind the FDA’s recent decision that people with severely weakened immune systems from organ transplants, cancer or other conditions need a third dose of the Pfizer or Moderna vaccine to have a chance at protection. In those people, it's not a booster but an extra amount they need up-front.
Won't antibodies wane again even after a booster?
Eventually. “We don’t know the duration of protection following the boosters,” cautioned Dr. William Moss of Johns Hopkins University.
But antibodies are only one defense. If an infection sneaks past, white blood cells called T cells help prevent serious illness by killing virus-infected cells. Another type called memory B cells jump into action to make lots of new antibodies.
Those back-up systems help explain why protection against severe COVID-19 is holding strong so far for most people. One hint of trouble: CDC has preliminary data that effectiveness against hospitalization in people 75 and older dropped slightly in July -- to 80% -- compared to 94% or higher for other adults.
“It’s much easier to protect against severe disease because all you need is immunologic memory. And I would imagine for a younger person that would last for a while," maybe years, said Dr. Paul Offit, a vaccine expert at the Children’s Hospital of Philadelphia.