New Omicron Subvariant Could Be More Contagious, Boston Doctors Say

Top Boston doctors are calling for alternative vaccine technology to provide longer-lasting immunity against COVID-19

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A descendant of the omicron variant could be more contagious than its predecessor and just as vaccine evasive, but Boston doctors continue to push people to get vaccinated.

Scientists and health officials around the world are keeping their eyes on the newest strain of the coronavirus, which scientists call BA.2. It's considered to be stealthier than the original version of omicron because particular genetic traits make it somewhat harder to detect.

"Right now it's pretty early on. We're watching things, the WHO is monitoring things very closely," Boston Medical Center's Dr. Sabrina Assoumou said. "But it's really important that we, you know, continue to get vaccinated and boosted so that if this becomes a problem, we're ready."

Meanwhile, drug companies like Pfizer and Moderna are working on variant-specific vaccines. Pfizer announced Tuesday that it began a study comparing its original COVID-19 vaccine with doses specially tweaked to match the hugely contagious omicron variant.

Top Boston doctors talked about variant-specific vaccines and their ability to stand up against new mutations of COVID-19 like the latest omicron subvariant during NBC10 Boston's weekly "COVID Q&A" series Tuesday.

What do we know about the new omicron subvariant?

The BA.2 or "stealth" variant has been found in at least 40 countries including the U.S. and it could be more contagious than omicron, Boston doctors say.

"Right now, from the data that we have -- you know it's still early -- but it appears to be more transmissible than omicron, believe it or not," Assoumou said. "What we've learned is that it has approximately 80 mutations compared to omicron it is kind of in the same family."

Whether the strain better evades vaccines or causes more severe disease remains to be determined, but Assoumou said preliminary data suggests the new strain is similar to omicron in both respects.

"The data that we have seems to suggest that that it has very similar severity to omicron," she said. "It seems that it's immune evasion is very similar to omicron, so it's going to be even more important to encourage people to get boosted."

Medical experts and public health officials alike continue to push people to get vaccinated and boosted with current vaccines, despite steady reports of breakthrough cases and developments of variant-specific vaccines.

"To be chasing every variant when the variants come and go as rapidly as they do is a bit like always fighting the last war."

Brigham and Women's Hospital Chief of Infectious Disease Dr. Daniel Kuritzkes

"There's very good evidence that, even with the current vaccines, if you've been boosted, you are highly protected from hospitalization and death," Brigham and Women's Hospital Chief of Infectious Disease Dr. Daniel Kuritzkes said.

In the last week, 46,092 new breakthrough cases -- infections in people who have been vaccinated -- were reported in Massachusetts, with 448 more vaccinated people hospitalized over the period, state health officials said Monday. The previous week saw 86,450 new COVID infections in vaccinated people.

While vaccinated people are getting COVID-19, doctors maintain that the vaccines still protect people against hospitalization and death. Last month, Massachusetts Department of Public Health officials released a study that found that 97% of breakthrough cases in the state did not become severely ill and rarely led to deaths, especially among young people.

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Will variant-specific vaccines help?

COVID-19 vaccine makers have been updating their shots to better match omicron in case global health authorities decide the change is needed. Boston doctors are skeptical about variant-specific vaccines as a long-term solution and instead call for further development of vaccine technology.

"To be chasing every variant when the variants come and go as rapidly as they do is a bit like always fighting the last war," Kuritzkes said. "And it's not at all clear that what's needed now, as omicron is going away, at least in parts of the country and parts of the world, is a vaccine that's tuned to omicron."

Dr. Shira Doron, hospital epidemiologist at Tufts Medical Center, called for further developed vaccine technology rather than exclusively relying on mRNA vaccines considering the virus' consistent mutations.

"Just as we can't predict the virus, you know, we can't predict what we're going to need vaccine-wise even a month from now," she said. "I think the sort of long-term better plan would be to keep studying vaccine technology, to keep on doing that development work to get us very improved vaccines. To get us vaccines that have more durability, things that will make it unnecessary to keep boosting as frequently."

Both Kuritzkes and Assoumou agreed that alternative vaccine technology is needed to provide more durable immunity. That could come in the form of a nasal vaccine, Doron said, which would knock out the ability of the virus to attach to the respiratory mucosa and cause infection.

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