Infectious omicron BA.2 now dominant in US, with coronavirus spring rise likely
LOS ANGELES — The highly infectious BA.2 omicron subvariant is now the dominant version of the coronavirus circulating in the United States, according to federal estimates, a development that is triggering fresh concerns of a potential springtime wave.
How big that potential upswing might prove to be remains the subject of much debate. Some experts believe California is well-armored against another significant surge — largely because the vast majority of residents have either been vaccinated or likely have some natural immunity left over from a recent infection.
But BA.2 has fueled substantial increases in other countries, demonstrating how readily the supercontagious subvariant can still spread.
“We will have a wave. The only question is how big it will be,” tweeted Dr. Eric Topol, director of the Scripps Research Translational Institute in La Jolla.
Added Scripps microbiologist Kristian Andersen: “I expect we’ll see a wave — I don’t know if it’ll be a surge.”
Over the week ending Saturday, BA.2 made up an estimated 55% of samples, according to the U.S. Centers for Disease Control and Prevention. That’s up from 39% the previous week.
In the Southwestern U.S. — which includes California, Arizona, Nevada and Hawaii — BA.2 made up an estimated 60.5%
