A more contagious version of the Omicron variant has spread in the United States

Scientists are closely watching the BA.2 strain of the Omicron variant, which has been quietly spreading throughout the United States.

BA.2 has now been detected in more than 30 states, makes up about 3.9 percent of new infections and appears to be multiplying rapidly, according to Centers for Disease Control and Prevention tracking data.

Samuel Scarpino, director of pathogen control at the Rockefeller Foundation, “If it doubles again to 8 percent, that means we are in an exponential growth phase and we may be staring at a new wave of Covid-19 in the United States,” he told NPR.

“And that is, of course, what we are really concerned about. We are all on the edge of our seats,” said Mr. Scarpino.

BA.2 is thought to be much more contagious than the previous Omicron strain, and is responsible for a new increase in Denmark.

However, fears of a new wave of Omicron in the United States may be avoided given vaccination coverage and immunity against previous infections.

Nathan Grubow, assistant professor of epidemiology at the Yale School of Public Health, said: NPR It will result in a long tail rather than another dash.

“A lot of us assumed it would take off in the US as quickly as it did in Europe and become the new dominant alternative,” Grupo said.

Other scientists warn that removing the mask could allow new species to spread.

The new strain also appears to be better at evading the immune system’s defense mechanisms than the original alternative, Omicron.

BA.2 is considered a “more secret” version of Omicron because some genetic traits make it somewhat difficult to detect.

Danish scientists reported this week that preliminary information indicates it may be 1.5 times more contagious than the original variant.

The US is still recording about 100,000 new cases and 2,000 deaths per day from the Omicron spike, according to the Covid Center for Disease Tracking and Prevention.