RALEIGH, N.C. (WNCN) — The latest CDC numbers show nearly a 20 percent increase in the average number of new COVID cases last week over the previous week, and some regions of the country are seeing new subvariants of the virus.

The New York State Health Department recently put out a warning about recently identified omicron subvariants, which reads, in part, “State health officials have determined that these highly contagious new variants are likely contributing to the rising cases.”

“It may be part of the virus but it’s also part of our social behavior,” noted Duke infectious disease specialist, Dr. Cameron Wolfe. “We’ve all dropped our masks for the most part. We started to congregate; lots of people are traveling.”

Wolfe says health experts in North Carolina are monitoring variants in other parts of the country and the world. “We don’t tend to get these things erupting here first,” he explained. “We often get a good lag time watching places like New York, Boston, London, South Africa occur first because there’s just more people packed in together, more chances for things to spread and transmit. We tend to be a more spaced-out state.”

Right now, the fast-spreading omicron subvariant known as BA.2 is most common in North Carolina.

“We’ve also seen a little bit of the subvariants called BA.3, and I think we’re looking hard for BA.4 BA.5,” Wolfe said, adding that there are also subvariants of BA.2.

As the virus continues to change, experts will work to learn as much as they can about the new strains.

“It’s not clear to us yet whether they’re more likely to cause severe illness,” he said. That does not look likely to be the case so far.”

It’s not clear whether North Carolina will see a substantial number of cases caused by the recently-identified subvariants. Wolfe said he says expects our vaccines will hold up against the new strains, protecting people who are vaccinated and boosted from severe illness and death.