The U.S. Food and Drug Administration advised drug manufacturers looking...

The U.S. Food and Drug Administration advised drug manufacturers looking to update their COVID-19 booster shots to make sure the new formulations include an omicron BA.4 and BA.5 component. Credit: Frank Hoermann / SVEN SIMON

New COVID-19 booster shots, specially formulated to target the highly contagious omicron variant and its subvariants, could be ready by the fall, health officials said.

Here is the latest information on what could be the newest weapon in battling the COVID-19 pandemic.

Why do we need an omicron-specific booster shot?

The vaccines and booster shots currently available were developed from the original strain of SARS-CoV-2, the virus that causes COVID-19. But over the past two-plus years, the virus has changed and mutated into new variations, known as variants. Earlier versions included the alpha and delta variants.

The omicron variant, first confirmed in the United States in December 2021, has proved to be highly transmissible. Some of its numerous subvariants comprise the majority of new COVID-19 infections.


  • With the majority of new COVID-19 infections caused by omicron subvariants, federal health officials have asked drug manufacturers to focus efforts on a new booster shot that targets them.
  • Both Pfizer BioNTech and Moderna said they are developing new booster shots that tests have shown provide some level of protection against omicron subvariants.
  • These new boosters could be available to the public by the fall.

Last month, the U.S. Food and Drug Administration advised drug manufacturers looking to update their COVID-19 booster shots to make sure the new formulations include an omicron BA.4 and BA.5 component.

In a memo outlining the FDA’s recommendation, Dr. Peter Marks, acting director at the FDA’s Office of Vaccines Research and Review and its Center for Biologics Evaluation and Research, said the current vaccine and boosters are “less effective against currently circulating virus variants than against previously circulating strains of virus.”

Dr. Uzma Syed, an infectious disease specialist at Good Samaritan Hospital in West Islip, said the existing COVID-19 vaccines and boosters have worked against the original strains, but not so much against omicron.

“Things have changed significantly since omicron came into the world,” Syed said. “We’re playing catchup here.” She pointed out the drug companies are working on "bivalent" booster shots which include components that protect against both omicron and the earlier versions of the virus.

Scientists are still studying omicron to fully understand why it is more infectious, but some believe the answers may be in the physical structure of the variant and its numerous mutations.

Dr. Uzma Syed, infectious disease specialist at Good Samaritan Hospital...

Dr. Uzma Syed, infectious disease specialist at Good Samaritan Hospital in West Islip. Credit: Debbie Egan-Chin

When will the omicron-specific booster shot be available?

The FDA has said it hopes the booster will be available by the fall, but there is no more specific time frame. Some published reports have said the Biden administration is pushing for a September unveiling, while others have said October or November is more likely.

In June, Pfizer BioNTech and Moderna, pharmaceutical firms behind two of the COVID-19 vaccines and boosters currently available, both announced development of omicron-adapted booster shots. They both reported improved immune response against omicron subvariants BA.4 and BA.5 in clinical trials of these new boosters. But both companies said the boosters were even more effective against an earlier subvariant, BA.1.

“There is a lot of pressure on these companies,” Syed said. “But I think it’s important that we try to stay ahead of this because we've made a lot of progress.

"There's a lot of opportunity here to save a lot of lives and have a product that’s offering more protection than what we have right now.”

What happens if another omicron subvariant becomes dominant by the fall instead of BA.4 and BA.5?

“As one of my friends put it, it’s like playing wack-a-mole the way we are chasing omicron,” said Dr. Leonard Krilov, a specialist in pediatric infectious diseases at NYU Langone Hospital – Long Island. “Concerns have been raised because now in India — and there are a few cases in the states — there’s the subsequent BA.2.75. Is that going to overtake BA.4 and BA.5? That’s the risky side of the game.”

Krilov said it’s somewhat similar to how flu vaccines are created on an annual basis.

“There is some guesswork trying to predict what the circulating strains, in this case variants, are going to be and get the best match we can,” he said. “In the years we have a good flu vaccine match, we get 60-plus percent protection. The years we don't have as good a match, it’s lower, but it's still something in preventing against severe disease. So, I think there's a good chance. It will be helpful. How helpful, I guess, based on this variation, makes it a little too hard to say right now.”

Both Syed and Krilov pointed out that vaccines and boosters are vital tools because even if they do not completely prevent infection from the virus, they protect against severe illness, hospitalization and death.

What if I just got a booster recently? Will I still be able to get the omicron-specific booster?

Krilov said it’s too soon to know whether the omicron booster would be first available to a certain age group, such as people over 50 and those who are immunocompromised, or to a larger swath of the public.

And it’s also unclear how soon they could receive it after previous boosters. Current CDC guidelines allow people over 50 to receive both the Moderna and Pfizer-BioNTech boosters five months after the final dose in a primary series and a second booster at least four months after the first. But that time frame is different for various age groups and immunocompromised people.

“We’re responding to shifting scenarios, shifting epidemiology every day,” Krilov said. “Although this is a milder disease than the original infections, it’s still not a mild disease, and there are long-term impacts. I think there is still a call to maximize our protection … we just have to keep our eyes on the moving target and make the best adjustments we can.”

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