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Fauci says omicron-specific vaccine is not yet needed because booster shots will protect

Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, said new data on the omicron variant of the coronavirus underscores the importance of booster shots. (Kevin Lamarque/Reuters)

Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, said Wednesday that an omicron-specific coronavirus vaccine is not needed at this time because early data indicates existing booster shots bolster disease-fighting antibodies.

The vaccines should be able to provide protection — although somewhat diminished — particularly against severe illness, Fauci said.

“Our booster vaccine regimens work against omicron. At this point, there is no need for a variant-specific booster,” Fauci said at a White House coronavirus briefing. “If you are unvaccinated, you are very vulnerable — not only to the existing delta surge we are experiencing, but also to omicron.”

Fauci reviewed a slew of data from the past week showing that antibodies spawned by two doses of messenger RNA vaccines — the Pfizer-BioNTech and Moderna shots — lose their potency against the omicron variant.

But laboratory data from the National Institutes of Health that Fauci showed revealed a Moderna booster shot restored antibodies capable of blocking omicron; those figures will be published in a preprint study in coming days, Fauci said. Similar data was presented on Pfizer-BioNTech boosters last week.

WHO Director General Tedros Adhanom Ghebreyesus said "vaccines alone will not get any country out of this crisis" during a news conference on Dec. 14. (Video: Reuters)

Such laboratory studies are clues, not final answers, to how vaccines will perform in protecting people. Most scientists have expected that even if the level of virus-blocking antibodies erodes, other parts of the immune system will continue to protect people against severe illness.

Breakthrough infections after vaccination would become far more common, but vaccinated people would remain largely protected against the worst outcomes. Emerging evidence has begun to support that idea.

Fauci showed real-world data from South Africa that after two doses of the Pfizer-BioNTech vaccine, people’s protection against symptomatic infection from omicron plummeted to about 30 percent. But even two doses were “maintaining a degree of protection” against hospitalization — they were 70 percent effective — though less strong than the protection provided against the delta variant.

Data from the United Kingdom showed that a Pfizer-BioNTech booster shot restored protection against symptomatic illness to about 75 percent.

Collectively, the data underscore the urgency for people who are eligible for booster shots to receive them, Fauci said.

Vaccine makers have been working to revise and test their shots to combat omicron in case they are needed. They are following a playbook they have run against other variants.

Moderna released a statement calling the data on boosters preliminary but “encouraging.” The company is formulating an omicron-specific shot, which would be ready to launch by March.

But Moderna is also examining shorter-term strategies, including whether a higher dose of the existing booster might be more protective. The company is also testing multi-strain boosters that the company developed to anticipate potential mutations in future variants. Those results are expected next week.

Kit Longley, a Pfizer spokesman, said the company was continuing to evaluate data on the performance of the vaccine against omicron.

“While the variant has not proven to escape the vaccine’s protection, we are continuing to advance the research and development of a variant-specific vaccine in the event that it is ever needed,” Longley said.

Coronavirus: What you need to know

The latest: The CDC has loosened many of its recommendations for battling the coronavirus, a strategic shift that puts more of the onus on individuals, rather than on schools, businesses and other institutions, to limit viral spread.

Variants: BA.5 is the most recent omicron subvariant, and it’s quickly become the dominant strain in the U.S. Here’s what to know about it, and why vaccines may only offer limited protection.

Vaccines: Vaccines: The Centers for Disease Control and Prevention recommends that everyone age 12 and older get an updated coronavirus booster shot designed to target both the original virus and the omicron variant circulating now. You’re eligible for the shot if it has been at least two months since your initial vaccine or your last booster. An initial vaccine series for children under 5, meanwhile, became available this summer. Here’s what to know about how vaccine efficacy could be affected by your prior infections and booster history.

Guidance: CDC guidelines have been confusing — if you get covid, here’s how to tell when you’re no longer contagious. We’ve also created a guide to help you decide when to keep wearing face coverings.

Where do things stand? See the latest coronavirus numbers in the U.S. and across the world. The omicron variant is behind much of the recent spread.

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