Fauci says Omicron-specific version of Covid-19 vaccines may not be necessary

Anthony Fauci isn’t convinced Covid-19 vaccine manufacturers are going to need to produce an Omicron-specific version of their vaccines.

Rather, the long-time director of the National Institutes of Allergy and Infectious Diseases suggested to STAT in an interview Thursday, it’s possible the current vaccines will provide enough protection against the new variant for most vaccinated and boosted individuals.

Fauci stressed that he was hypothesizing, based on how the vaccines have held up against other SARS-CoV-2 variants. Studies will need to be done, he insisted. And manufacturers are working on and will test versions of their vaccines based on the mutation-studded Omicron spike protein. That’s prudent, he said.

“The companies are going to be making variant specific boosters,” Fauci told STAT. But “what I think is something that we need to keep our eye on [is] it could be that things turn out better than we expected.”

Omicron was first identified in late November in Botswana and South Africa, and was declared a variant of concern by the World Health Organization on Nov. 26. On Wednesday, WHO Director-General Tedros Adhanom Ghebreyesus said the variant has been found to be circulating in 57 countries. That number includes the United States. In parts of Europe, the variant appears to be picking up steam.

The many differences between this version of the virus and others that pre-date it — most especially the original strain that emerged from Wuhan, China, in early 2020 — have led to speculation about whether the target of the existing Covid vaccines should be updated to focus on Omicron.

But on Wednesday, Pfizer and BioNTech released data suggesting that while two doses of their vaccine might not be enough to stave off Omicron viruses, people who had received a booster dose may have adequate protection. And in an interview with STAT, Kathrin Jansen, Pfizer’s head of vaccine research, said she hasn’t yet developed a gut feeling about whether the vaccine will need to be updated.

“You know, now we get ready. We look at the evidence. I think we are in a position to address it. But I do not have a good sense right now if we want to, need to, should have to. You have to give us a little bit more time,” Jansen said.

Fauci’s views are similar. He noted that many studies have shown that the vaccines can protect against a range of variants that have emerged.

“I’m not so sure that we’re going to have to get a variant-specific boost vaccine to get an adequate protection from Omicron,” he said. “Because if you look at protection against variants, it appears to relate to the level of immunity and the breadth of the immunity that any given vaccine can instill on you.”

“We’ve seen also when you boost yet again with the ancestral strain,” — vaccines that target the Wuhan virus — “not with a variant-specific strain, you get a rather dramatic multi-, multi-fold increase [in antibodies] … what I would call a projection or a prediction of protection,” Fauci said.

He pointed to a study from South Africa released earlier this week. It reported that, when blood from people who had been vaccinated was exposed to the Omicron virus, there was a substantial reduction in neutralization as compared to the vaccine strain. (The study, which has not yet been peer-reviewed, did not include people who had been given booster doses.)

But the neutralizing capacity of blood drawn from people who had been vaccinated after having had a Covid infection told a different story. “When you looked at people who were vaccinated and infected, they did pretty well. And to me, vaccinated and infected is equivalent to getting boosted,” Fauci said.