Two sublineages of the BA.2 omicron subvariant are circulating in New York and are likely factors in the state's rising COVID-19 cases, state health officials said April 13.
The subvariants — BA.2.12 and BA.2.12.1 — are estimated to have a 23 percent to 27 percent growth advantage over BA.2, which was already more transmissible than the original omicron strain. Based on sequencing data, state health officials said they've determined that "these highly contagious new variants are likely contributing to the rising cases."
Officials estimate the BA.2 sublineages collectively account for more than 70 percent of cases in March in central New York. April data indicates that figure is now more than 90 percent.
"The department's findings are the first reported instances of significant community spread due to the new subvariants in the U.S.," officials said in a news release. "At this time, there is no evidence of increased disease severity by these subvariants, though the department is closely monitoring for any changes."
New York's daily average for new COVID-19 cases on April 13 was 5,286, reflecting a 77 percent increase in the last 14 days, data from The New York Times shows. Case increases in several Northeastern states account for much of the nation's overall rising infection numbers.