(CTN News) – Omicron subvariants demonstrate immune-dodging abilities, posing a threat to vaccinated and previously infected individuals.
According to the Centers for Disease Control and Prevention, BA.4.6 accounted for just over 12% of new Covid cases in the US. BA.5, on the other hand, has been detected in nearly 68% of new cases.
Globally, experts are keeping an eye on many more strains than these. Omicron subvariants that have piqued scientists’ interest read like a viral alphabet soup: BQ.1, BQ.1.1, BF.7. Each accounts for around 5% of U.S. cases.
Since the omicron variant emerged, Covid has been down, with subvariants separating off.
Covid is no longer identified by Greek letters like alpha and delta. Since the omicron variant emerged, it’s been omicron down, with subvariants splitting off into their own.
Dr. Dan Barouch, director of the Beth Israel Deaconess Medical Center’s Center for Virology and Vaccine Research, said it’s amazing how fast the virus keeps mutating. “This is viral evolution on steroids.”
Barouch’s study was small, involving just 35 people who’d either had the Covid vaccine or an omicron infection.
He said that Omicron is evolving in a way that makes it more transmissible and better at escaping vaccines and immune responses. “The results might be a harbinger of worse variants to come.”
A virus can mutate randomly, but mutations that give it an edge over the immune system, vaccines, or treatments tend to stick around.
“The virus is rapidly diversifying,” says Bill Hanage, associate professor of epidemiology at Harvard T.H. Chan.
Further complicating things, people have different immunity levels depending on which vaccines they got (or didn’t get) and how many infections they’ve had.
“Many hopeful monsters can emerge and transmit because of a patchwork of immunity,” Hanage said.
Covid’s new booster shots target both BA.4 and BA.5. However, there’s no data on how they work against BA.4 and BA.5.
During a media briefing Wednesday, Maria Van Kerkhove, head of the WHO’s emerging diseases and zoonosis unit, said the WHO tracks 300 omicron subvariants worldwide. She said they’re all more transmissible.
Adriana Heguy, a pathology professor at NYU Grossman School of Medicine and director of the Genome Technology Center, says her team found omicron subvariants XBB and XAZ. Those aren’t listed in the CDC’s variant tracker yet.
“Everything starts in New York,” Heguy said.
Subvariants are spreading worldwide, but there’s no evidence they’re making people sick.
“There’s no change in severity yet,” Van Kerkhove said.
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