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Early surveillance indicates San Diego wave is coming as BA.2 becomes dominant COVID-19 variant in US

A woman receives a COVID-19 vaccine from Cal Fire in Julian, Calif. Feb. 3, 2021.
Matt Hoffman
A woman receives a COVID-19 vaccine from Cal Fire in Julian, Calif. Feb. 3, 2021.

Just as U.S. regulators approved another booster dose of the COVID-19 vaccines from Pfizer and Moderna, BA.2 — an omicron variant — has become the most common in the U.S.

RELATED: The more contagious BA.2 version of omicron is now the most common in the U.S.

Dr. Eric Topol, director of the Scripps Research Translational Institute in La Jolla, said even though the BA.2 variant is more contagious than the original omicron variant, vaccine protection is similar.


"There is a doubling of viral load ... that is the amount of viral copies we carry in our upper airway. And that explains, I think, the high transmission," Topol said. "It's hard to know how bad this wave is going to be because we've recently gotten through such a big one with the omicron BA.1. And in fact, it's estimated that about 40% of Americans got BA.1 and there was a huge number of breakthrough infections because it just spread so easily. This one can be worse but we have some immunity built."

RELATED: FDA OKs another Pfizer, Moderna COVID booster for 50 and up

Topol joined KPBS Midday Edition to talk about the latest COVID-19 updates.

"The most important thing are the boosters. Those people who have been vaccinated, they have to get a booster. We have a terrible rate of people getting boosters in everyone who's had two shots," Topol said. "The older the age, the more benefit. We have three studies from Israel on the fourth shot, the most recent in which shows that it protects against death in people who are 60 and older, substantially, nearly an 80% reduction."

Topol said the only reason people should not get the booster is if they did not tolerate previous doses well.