News, highly transmissible forms of Omicron may pose latest covid-19 threat.

Disease trackers are monitoring the spread of new, highly transmissible versions of the omicron variant in New York state and Europe, the latest evidence of the coronavirus's ability to overhaul its genetic profile and pose a fresh threat.

It is too soon to predict how far the new subvariants might spread and how sick they might make people, said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.

"When you look at what's happening right now and try to tell the story of what might occur, you're challenged," he said. For now, scientists are left "watching and learning," Osterholm added.

The first communities in the United States that have said they are contending with the new omicron subvariants are in central New York, around Syracuse and Lake Ontario.

New York state officials this week announced that two new omicron subvariants, dubbed BA.2.12 and BA.2.12.1, have become the dominant forms of the coronavirus in the central part of the state. For weeks, infection rates in central New York have been at least twice the state average, according to data from the state health department.

The new omicron sublineages in New York have picked up mutations that may help the virus enter cells faster and evade vaccine- and infection-boosted immunity, said Andy Pekosz, a virologist at the Johns Hopkins Bloomberg School of Public Health.

"Whenever we see those mutations, we're a little bit concerned, but it's hard right now to really estimate how big of a concern those variants will be," Pekosz said.

State officials said that the subvariants are spreading 23 to 27% more rapidly than the original BA.2 omicron variant and that the subvariants are contributing to rising case numbers.

"The Department's findings are the first reported instances of significant community spread due to the new subvariants in the United States," New York state health officials said in a news release Wednesday. "At this time, there is no evidence of increased disease severity by these subvariants, though the Department is closely monitoring for any changes."

In March, the two subvariants accounted for more than 70% of reported covid-19 cases in central New York. So far in April, the data show an increase to 90% of all new cases.

By Sindile Mhlanga