SAN FRANCISCO (KGO) -- It used to be that once infected with COVID-19, your body would build up enough immunity to avoid another infection for weeks and sometimes even months, but scientists are noticing that omicron's subvariant BA.2.12.1 is changing that.
"You don't have great protection having been infected with BA.1," said Dr. Warner C. Greene, senior investigator for the Gladstone Institutes.
Meaning, even if you had COVID you can still get infected with BA.2.12.1.
"It's immunosuppressive. It's acquiring these mutations which make it like a stealth virus. We have our immune system at the ready trying to prevent these infections, but the virus is now learning how to elude the antibodies. It has less success against the T-cells thank goodness," said Dr. Greene.
Vaccines continue to protect against severe disease and hospitalizations, but Dr. Greene believes more people will get reinfected.
"Omicron if its 1 then BA.2 which came around next was 30% more infectious. This new subvariant is 25% yet more infectious," said Dr. Greene.
Nationwide BA.2.12.1 makes up 56% of new COVID cases. In California, according to the latest modeling this subvariant makes up about half of cases.
Prof. Alexandria Boehm with Stanford's Department of Civil and Environmental Engineering is seeing that increase in our wastewater.
"The concentrations look like they are doubling every two weeks," said Professor Boehm.
Concentration levels show that BA.1 is almost non-existent. BA.2 which includes BA.2.12.1 has taken over.
"In Yolo County where the concentration in the wastewater right now are almost as high as they were during the omicron surge in Davis. Then Oceanside in San Francisco is always been sort of a centennial plant for us where things happen there first. You can see that the levels at Oceanside in the wastewater are currently twice what they were two weeks ago," said Professor Boehm.
Professor Boehm said they also detected omicron's BA.4 and BA.5 in the Bay Area.
"BA.4 and BA.5 were other sublineages of omicron that have started to emerge in South Africa that have taken over the BA.2 sublineages. We have detected BA.4 or BA.5 in the water in San Jose," said Professor Boehm.
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