COVID Q&A

Do Existing COVID Vaccines Protect Against Omicron? Boston Doctors Explain

Experts don't yet know whether the omicron variant can evade the existing COVID-19 vaccines, yet doctors continue to urge people to get the shot

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Three top Boston doctors explain what the new omicron variant is, whether it’s already in the U.S., what the symptoms are and if vaccines protect against it on the weekly “COVID Q&A” series.

Politicians and medical experts in Massachusetts are urging people to get vaccinated against COVID-19 amid growing concern over the omicron variant, but whether the vaccines protect against the new strain remains unclear.

First detected in South Africa, the highly mutated variant has been found in 24 countries so far. Federal officials confirmed the first case in the United States on Wednesday.

NBC10 Boston asked three top Boston doctors on Tuesday to explain what we do know about the omicron variant and coronavirus vaccine efficacy in the weekly "COVID Q&A" series.

Can Omicron Evade COVID Vaccines?

Experts say they aren't sure if the omicron variant can evade the existing COVID-19 vaccines or natural antibodies.

"We just don't know," said Dr. David Hamer, an infectious disease specialist at Boston Medical Center.

Yet doctors continue to urge people to get boosted and vaccinated against the coronavirus. Hamer noted that, while omicron has been classified as a "variant of concern" by the World Health Organization, delta remains the predominant strain.

Politicians and medical experts in Massachusetts are urging people to get the COVID-19 vaccine booster shot as the new omicron variant creates uncertainty across the state, the nation and around the globe.

"First of all, we should continue to try and increase vaccination coverage for those who have not had it. We should be thinking about boosters for those who are due for boosters. And that's more just because delta is still circulating," Hamer said. "Delta is predominant."

New England states have seen a steady rise in coronavirus cases and hospitalizations, including Maine, Vermont and to a lesser extent, New Hampshire, Hamer said. Massachusetts' COVID metrics have also been rising lately as hospitals struggle with bed and staffing shortages.

"A lot of the hospitalizations are people that have not been vaccinated," Hamer said. "And so it still remains our best tool to limit the spread of disease to decrease the risk of their disease, hospitalization and death. And we don't know whether these vaccines, as currently formulated, will protect against this new variant, but right now we're still dealing with delta primarily in the U.S."

Dr. Shira Doron, the hospital epidemiologist at Tufts Medical Center, said even if the vaccines prove to be less effective against the new strain, that can often be overcome with a booster, even one of the original formulation of the vaccine.

"I think it's important to point out that it isn't an on off switch. It isn't a black and white question," she said. "It isn't going to be the case that, if this variant is immune-evading, that that means the vaccines are ineffective and useless."

More from the COVID Q&A series

A panel of Boston-based doctors talk about everything related to the COVID-19 pandemic every Tuesday at 10:30 a.m.

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Meanwhile, pharmaceutical companies like Moderna, Pfizer and Johnson & Johnson are already adjusting their existing COVID-19 vaccines to better attack the omicron variant.

"That's really what the companies are rushing to figure out right now," Doron said. "Are the existing vaccines -- boosted or unboosted -- with the original formulation, capable of neutralizing this variant? And then if not, would an additional booster with a more targeted formulation of vaccine be warranted? And if so, then they can get that produced fairly quickly by the beginning of 2022."

Dr. Daniel Kuritzkes, Brigham and Women's Hospital's chief of infectious disease, noted that the virus is constantly mutating and will continue to do so.

"I think the emergence of omicron makes the point even more strongly that we are going to continue to see the circulation of COVID-19, and the emergence of new variants, so long as there are susceptible populations," Kuritzkes said. "And the most important thing that we can do to stop this from happening and to reduce the risk of it happening again is to ensure that we continue working to vaccinate as many unvaccinated people as possible, and not just here in the United States, but around the world."

Will Omicron Replace Delta as the Dominant Strain?

The variant has more than 30 mutations to the spike protein alone, which is the key part of the virus that allows it to bind to human cells and infect the body, Hamer said.

The spike protein's many mutations have scientists worried that it will be far more infectious than the highly contagious delta variant that's caused a surge in cases across globe in recent months.

"The real question is going to be, 'Is omicron is better at transmission than delta is -- is it gong to displace delta?" Hamer said. "Or will delta remain the dominant strain that we have to deal with?"

The Boston-based infectious disease experts noted, however, that coronavirus strains can be unpredictable.

Kuritzkes pointed to past coronavirus strains, like the mu variant, that have caused concern but ultimately did not amount to much.

As cases of the delta variant continue to raise concerns across the U.S., the latest variant to take hold in the country, many are wondering what other variants are out there and which should we be concerned about?

Mu surfaced in September as a classified "variant of interest" from the World Health Organization and was initially thought to be resistant to vaccines and other means of immunity.

"There was a lot of concern about that," Hamer said. "Then it just sort of fizzled out. It may be that that virus is not as fit, not as able to transmit and therefore delta has a fitness advantage."

"We really have to see if it actually outcompetes delta anywhere that is still struggling with delta," Doron said.