Expert describes pace of BA.2 COVID cases across Bay Area: 'doubling over two weeks'

As omicron's sub-variant BA.2 continues to spread, the CDC confirms the strain is now responsible for 86% of US coronavirus cases.
SAN FRANCISCO (KGO) -- As omicron's sub-variant BA.2 continues to spread, the CDC confirms this strain is now responsible for 86% of coronavirus cases nationwide.

Locally, researchers are also seeing an uptick in cases.

RELATED: Dozens of Marin Co. students test positive for COVID after school trip to DC

"Most of the cases in the Bay Area and Sacramento are caused by BA.2," said Alexandria Boehm, Professor of Stanford's Department of Civil and Environmental Engineering.

Professor Boehm is part of a team that's tracking 12 water plants in Northern California.

Luz Pena: "How fast are they rising?"

Professor Boehm: "Based on the water it looks like perhaps they are doubling over two weeks."

Right now, they're detecting a large increase in Gilroy.

"COVID-19 is not gone and it's going to continue to probably affect our lives into the near future," said Professor Boehm.

Today the CDC extended the federal mask mandate for planes, trains and buses until at least May 3.

"What the federal government and the state government should do is dial up and down the mask requirements as we are seeing cases rise and fall. If cases are going up I do think its justified we make sure to keep people safe on public transit, airplanes and other close environments in doors," said Joe Derisi, President of the CZ BioHub & UCSF Professor of Biochemistry and Biophysics.

RELATED: CDC to extend federal mask mandate on airplanes, transit for 2 weeks

As Passover and Easter approaches Professor Derisi President of the CZ BioHub recommends, "If you are getting together with a large group of people at your house, consider getting a rapid antigen test for people. Then everybody is negative coming in through the door with good confidence not wear a mask inside."

Professor DeRisi believes there could be a small increase of BA. 2 after the holidays.

"We probably will see a slight increase here in the Bay Area," said DeRisi and added, "It may be a little different in other parts of the country. We are not predicting at this time an omicron January-style peak like we saw before because there is already a large number of people that got infected in January that will have some new immunity to BA.2, plus their vaccines."

Professor Boehm said influenza cases are slightly increasing as well. An uptick that goes in hand with the lift of mask mandates.

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