By Erin Petenko/VTDigger
A new subvariant of the now-dominant Omicron strain was detected in Vermont last week as part of genomic sequencing, the Department of Health reported Friday, Jan. 28.
The Broad Institute identified the subvariant in a sample sent to them as part of Vermont’s “ongoing sequencing efforts,” according to health department spokesperson Ben Truman.
The subvariant has been identified in about two dozen other U.S. states so far, but its prevalence remains below 1% in every state, according to Outbreak.Info, a multi-lab research cooperative. It’s also been detected in 53 countries besides the United States.
BA.2 is not defined as a new variant but instead called a subvariant or sublineage of the main Omicron strain, called BA.1. The latest research shows that it has about 85 mutations from BA.1, enough to make it distinct from other subtypes but not yet enough to classify it as a new variant.
Scientific understanding of the subvariant and its effects is still evolving.
“It is possible that BA.2 is a more contagious version of the Omicron variant,” Truman said via email. “There is no strong evidence at this time that it leads to more severe illness or is better at evading immunity.”
“Studies to understand the characteristics of BA.2 are still in their early stages, including about how well it spreads and if there is any impact on testing and vaccine effectiveness,” he wrote. “At this time we have not seen areas that are cause for alarm.”
The most evidence available comes from Denmark, where BA.2 now forms more than half of new infections. Danish Health Minister Magnus Heunicke said this week that the subvariant does appear to be more transmissible but no more severe than the main Omicron strain. The country planned to lift all Covid-19 restrictions Feb. 1.
The U.S. Centers for Disease Control and Prevention did not include BA.2 in its variant tracker as of Friday, but it found that Omicron comprises more than 99% of all samples in the New England region.
