Health officials warn of 'stealth omicron' COVID-19 variant spreading in Georgia

ATLANTA - Health officials warn that we could see another surge in COVID-19 cases soon as a new variant begins to become ever more prevalent.

The strain, a descendant  of omicron known as BA.2 has already been driving up case counts overseas and caused lockdowns in China, Japan, and South Korea.

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Experts think it will likely bring rising cases in the U.S., where over the last two months cases have rapidly declined - reaching the lowest levels since last July before the delta variant wave.

The most recent data from the Centers for Disease Control and Prevention shows about 23% of new U.S. COVID cases are BA.2. In the Southeast, the number is 12.4% and growing.

Health officials say they are watching the new data carefully but have not seen a reason to go back to the level of masking and restrictions previously seen in the pandemic.

In Georgia, most of the state remains at a low COVID-19 community level outside of a few counties in south Georgia and three in north Georgia that remain at medium levels. Only Colquitt County has a high community level of COVID-19, the CDC says.

Officials say while levels are lower, individuals should remain vigilant and remember that vaccines and boosters offer protection against the worst effects of COVID-19, no matter the variant.

What's known about BA.2

BA.2 has lots of mutations. It’s been dubbed "stealth" because it lacks a genetic quirk of the original omicron that allowed health officials to rapidly differentiate it from delta using a certain PCR test. So while the test can detect a BA.2 infection, it looks like a delta infection.

Initial research suggests BA.2 is more transmissible than the original omicron — about 30% more contagious by one estimate.

But vaccines can protect people from getting sick. Scientists in the United Kingdom found that they provide the same level of protection from both types of omicron.

A bout with the original omicron also seems to provide "strong protection" against reinfection with BA.2, according to early studies cited by the WHO.

But getting BA.2 after infection from the original omicron strain is possible, says new research out of Denmark. Study authors noted 187 total reinfections, including 47 with BA.2 occurring shortly after a bout the original strain, mostly in young, unvaccinated people with mild disease. They concluded that such reinfections do occur but are rare. Like other early studies on BA.2, this one has been posted online but not reviewed by independent scientists.

Does BA.2 make you sicker?

A Japanese lab study suggests that it could, based on experiments with hamsters. Researchers concluded that the risk for global health "is potentially higher" from BA.2 and proposed that it be given its own Greek letter – a designation for globally significant "variants of concern." WHO’s technical group said BA.2 should remain under the omicron umbrella.

Though the severity experiments were conducted in animals, the study is "not something to discount," said Dr. Eric Topol of Scripps Research Translational Institute. "We should keep an open mind and keep assessing this."

But scientists are finding something different when they look at people. An initial analysis in Denmark showed no differences in hospitalizations for BA.2 compared with the original omicron, which tends to generally cause milder disease than the delta variant. More recently, researchers in South Africa found much the same: a similar risk of hospitalization and severe disease with the original omicron variant and BA.2.

"We always have to interpret studies in animals with caution," said Dr. Wesley Long, a pathologist at Houston Methodist in Texas.. "I place more weight in studies of actual patients and what they’re experiencing."

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The Associated Press contributed to this report.