Millions of Americans can now receive a second COVID-19 booster shot, but not everyone is eligible. A new decision on eligibility could be coming soon, however.
Chicago's top doctor said the rest of the population may not see authorization for a fourth COVID shot until the fall.
"I don't want people to think that this is something that everybody has to get," Chicago Department of Public Health Commissioner Dr. Allison Arwady said during a COVID-19 update Thursday. "My expectation is that perhaps in the fall, we may see a new formulation of a COVID vaccine that is more specific for variants. There hasn't been a decision made on that, but I think we may be, you know, ahead of winter, looking at a booster again for everybody."
The federal government is expected to evaluate whether to recommend fourth vaccine doses for all Americans, and could choose to issue those recommendations during the fall when more Americans are indoors as the weather cools.
This week, the government will hold a public meeting to debate if everyone eventually needs a fourth dose, possibly in the fall, of the original vaccine or an updated shot.
Currently, Americans 50 and older can get a second COVID-19 booster if it’s been at least four months since their last vaccination.
The Food and Drug Administration last week authorized an extra dose of the Pfizer or Moderna vaccine for that age group and for certain younger people with severely weakened immune systems.
The Centers for Disease Control and Prevention later recommended the extra shot as an option but stopped short of urging that those eligible rush out and get it right away.
Even if higher-risk Americans get boosted now, FDA vaccine chief Dr. Peter Marks said they may need yet another dose in the fall if regulators decide to tweak the vaccine.
For that effort, studies in people — of omicron-targeted shots alone or in combination with the original vaccine — are underway. The National Institutes of Health recently tested monkeys and found “no significant advantage” to using a booster that targets just omicron.
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Currently, the fourth dose being offered to eligible Americans is the same as the original booster.
"I'm going to be honest with you - this is the same vaccine formulation that we've been using all along. It's the same Pfizer the same Moderna dose and you do probably get some additional protection, but it's not as great additional protection as you got from the first the second and then the third," she said. "The CDC and the FDA have decided to make it available because in Israel, where they did a fourth dose, they saw people who got the fourth dose were less likely to die of COVID. That said, I think people who choose to get a fourth dose are probably also being more careful about COVID In some ways."
Arwady noted that those who are eligible for a second booster may get some protection from the fourth shot, particularly as cases begin to climb in both the city and the state, sparked by the BA.2 omicron subvariant.
"I'd say if you're over 65, or you're over 50 with an underlying condition, certainly if you're immunocompromised, I don't think there's a downside," she said . "There's not a safety concern. It doesn't hurt your immune system. It's free. It's available. Getting a second COVID booster dose can help. But the most important thing is that everybody in your network has had those first three."
Dr. Rochelle Walensky, CDC's director, said it was especially important for older Americans — those 65 and older — and the 50-somethings with chronic illnesses such as heart disease or diabetes to consider another shot.
“They are the most likely to benefit from receiving an additional booster dose at this time,” Walensky said.
There's evidence protection can wane particularly in higher-risk groups, and for them another booster “will help save lives," Marks said.
The move toward additional boosters comes at a time of great uncertainty, with limited evidence to tell how much benefit an extra dose right now could offer. COVID-19 cases have dropped to low levels in the U.S., but all vaccines are less powerful against newer mutants than earlier versions of the virus — and health officials are warily watching an omicron sibling that's causing worrisome jumps in infections in other countries.
During the U.S. omicron wave, two doses were nearly 80% effective against needing a ventilator or death — and a booster pushed that protection to 94%, the CDC recently reported. Vaccine effectiveness was lowest — 74% — in immune-compromised people, the vast majority of whom hadn’t gotten a third dose.
To evaluate an extra booster, U.S. officials looked to Israel, which opened a fourth dose to people 60 and older during the omicron surge. The FDA said no new safety concerns emerged in a review of 700,000 fourth doses administered.
Preliminary data posted online last week suggested some benefit: Israeli researchers counted 92 deaths among more than 328,000 people who got the extra shot, compared to 232 deaths among 234,000 people who skipped the fourth dose.
What’s far from clear is how long any extra benefit from another booster would last, and thus when to get it.
“The ‘when’ is a really difficult part. Ideally we would time booster doses right before surges but we don’t always know when that’s going to be,” said Dr. William Moss, a vaccine expert at the Johns Hopkins Bloomberg School of Public Health.