WASHINGTON (AP) — The US on Wednesday approved the first update of COVID-19 vaccines, booster doses targeting today’s most common strain of omicron. Shooting can start in a few days.
Food and Drug Administration move changes recipe from shots made by Pfizer and rival Moderna that have already saved millions of lives. The hope is that the modified boosters will weaken yet another winter wave – and help tackle the widely spread BA.5-omicron relative.
“These updated boosters give us an opportunity to move forward” on the next COVID-19 wave, said FDA Commissioner Dr. Robert Califf.
Until now, COVID-19 vaccines have targeted the original coronavirus strain, even as wildly different mutants emerged. The new American boosters are combination or ‘bivalent’ shots. They contain half that original vaccine recipe and half the protection against the latest ommicron versions, BA.4 and BA.5, which are considered the most contagious to date.
The purpose of the combination is to increase crotch protection against multiple variants.
“It really offers the greatest chance of protection,” Annaliesa Anderson, Pfizer’s head of vaccine, told The Associated Press.
The updated boosters are only for people who have already had their primary vaccinations, using the original vaccines. Doses made by Pfizer and its partner BioNTech are for anyone 12 years and older, while Moderna’s updated injections are for adults – if it’s been at least two months since their last primary vaccination or their last booster. They should not be used for the first vaccinations.
There’s one more step before a fall booster campaign kicks off: The Centers for Disease Control and Prevention must recommend who should get the extra shot. An influential CDC advisory panel will debate the evidence Thursday — including whether people at high risk for COVID-19 should go first.
The US has purchased more than 170 million doses from the two companies. Pfizer said it could ship up to 15 million of those doses by the end of next week. Moderna didn’t immediately say how many doses are ready to ship, but that some will be available “in the next few days.”
The big question is whether people who have had enough of vaccinations will roll up their sleeves again. Only half of vaccinated Americans got the first recommended booster dose, and only a third of those over 50 who were urged to get a second booster got it.
Here’s the problem: The original vaccines still provide strong protection against serious illness and death from COVID-19 for generally healthy people, especially if they’ve received that all-important first booster dose. It’s not clear how much more benefit an updated booster will bring — other than a temporary jump in antibodies that can fend off an omicron infection.
Still, “people need to realize that this is a different kind of booster than was previously available. It will work better at protecting against omicron,” said virologist Andrew Pekosz of the Johns Hopkins Bloomberg School of Public Health.
Even people who had a previous omicron version can still get infected again, so “you should definitely go for the booster even if you’ve been infected in the past year,” Pekosz added. He thinks that “if we can get a good buy-in to use this, maybe we can really make a dent” in COVID-19 cases.
The FDA approved the changes ahead of human studies, a step toward eventually dealing with COVID-19 vaccine updates, more like annual changes to flu shots.
dr. Peter Marks, head of the FDA vaccine, emphasized that the agency considered “the totality” of evidence. Pfizer and Moderna have previously brewed vaccine doses that were updated to match previous mutants — including the omicron strain called BA.1 that struck last winter — and tested them in humans. Those previous prescription changes were safe, and the BA.1 version significantly increased virus-fighting antibodies — more than any other dose of the original vaccine — though less that recognized today’s genetically distinct BA.4 and BA.5 strains.
But instead of using those BA.1 shots, the FDA ordered the companies to brew even more up-to-date doses targeting those latest ommicron mutants, sparking a race to roll them out. Rather than wait a few more months for additional human studies of that very similar recipe tweak, Marks said animal studies showed the latest update triggers “a very good immune response.”
“You have to refresh the immune system with what’s actually circulating,” Marks said. That’s why the FDA also no longer allows boosters made with the original recipe for ages 12 and older.
The hope, Marks said, is that a vaccine tailored to the currently distributed variants can do a better job of fighting infection, not just a serious illness, at least for a while.
What’s next? Even as custom shots roll out, Moderna and Pfizer are conducting human studies to assess their worth, including how they hold up when a new mutant comes along.
And for children, Pfizer plans to ask the FDA to allow updated boosters for 5- to 11-year-olds in early October.
It’s the first US update to the COVID-19 vaccine prescription, an important but anticipated next step — like how flu vaccines are updated every year.
And the US is not alone. Britain recently decided to offer adults over 50 a booster option other than Moderna, a combo shot targeting that original BA.1 omicron strain. European regulators are considering allowing one or both of the updated formulas.
AP Health writer Matthew Perrone contributed to this report.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.