Mutations in the Omicron subvariant of COVID can evade both vaccinated and unvaccinated immune systems and lead to reinfection, a study shows.
Currently, BA.5 is the dominant global Omicron According to Wednesday’s New England Journal of Medicine.
However, BA.4.6 is a mutation of BA.4 and has recently been predominant in some regions of BA.5 (including in usan overview of the report.
The variant has been detected in over 12% of new products Coronavirus disease U.S. cases, according to the Centers for Disease Control and Prevention.
Whether it can escape antibodies acquired through prior COVID infection or vaccination remains unknown, but a small study outlined in the report suggests it might.
Data from blood samples from 35 people who had recently been infected with COVID or who had received the original Moderna vaccine and were boosted showed that antibodies against BA.4.6 were about two times lower than those against BA.5.
“This suggests that Omicron continues to evolve and continue to evolve in a way that is more transmissible and more effective at evading vaccines and immune responses,” said study author Dan Barouch, PhD, director of the Beth Israel Center for Virology and Vaccine Research at Boston Deaconess Medical Center.
“The results actually portend new variants that may be more worrying,” he added.
Study participants were infected with the Omicron sub-variants BA.1 or BA.2.
It remains to be determined whether BA.4.6 can escape the immune protection conferred by infection with BA.5 or a vaccine booster containing an immunogen against BA.5.
“The Viral Evolution of Steroids”
Experts are also keeping a close eye on other Omicron sub-variants in circulation.
According to the CDC, BQ.1 accounted for more than 5% of new U.S. cases, up from 3% the week before and 1-2% the week before.
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A similar picture can be seen in BA.7, which accounted for more than 5% of new cases in the United States, up from 4% in the previous week and 3% in the previous week.
“It’s amazing to see how the virus continues to mutate at such a rapid rate,” Dr. Barouch said, adding: “This is essentially viral evolution on steroids.”
The report concluded that the virus continued to develop.
“This virus is rapidly diversifying,” said Bill Hanage, associate professor of epidemiology at Harvard’s TH Chan School of Public Health.