Omicron subvariants reflect a ‘viral evolution on steroids’

A new study suggests that the subvariant BA.4.6 can cause reinfections. A slew of other subvariants on the horizon may do the same.

A report published Wednesday in the New England Journal of Medicine suggests that the subvariant, called BA.4.6, could drive reinfections.

Gone are the days of identifying Covid by Greek letters, such as alpha and delta. Ever since the omicron variant emerged, it’s been omicron all the way down, with omicron subvariants splitting off into their own subvariants. 

“It’s astonishing to see how the virus keeps mutating at such a rapid rate,” said study author Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at the Beth Israel Deaconess Medical Center in Boston. “This is essentially viral evolution on steroids.”

Barouch’s study was small, including just 35 people who’d had either the Covid vaccine or an omicron infection. Most, regardless of prior infection, had at least three doses of Covid vaccine. Blood samples showed that antibodies meant to neutralize BA.4.6 were about twofold lower than antibodies for BA.5.

“This suggests that omicron continues to evolve and continues to evolve in a way that becomes more transmissible and more effective at escaping vaccines and immune responses,” he said. “The results are actually a harbinger to new variants that might be even more worrisome.”

The updated Covid booster shots, which became available just last month, target both BA.4 and BA.5. But there’s still no data on how the new shots work against BA.4 and BA.5, not to mention the slew of other subvariants.

https://www.nbcnews.com/health/health-news/omicron-subvariants-ba46-can-evade-immunity-may-lead-reinfections-rcna52950