A health expert is describing one of the COVID-19 variants that is ripping through parts of the country as a game change. Now, he says it’s enough to re-evaluate sending kids back to school.

"Please understand, this B.1.1.7 variant is a brand new ballgame,” says Michael Osterholm, epidemiologist at NBC’s Meet the Press. The variant B.1.1.7 is the COVID-19 variant first identified in the UK, and Osterholm is making the rounds to talk about one of the challenges of the variant.

"It infects kids very readily. Unlike previous strains of the virus, we didn't see children under eighth grade get infected often, or they were not frequently very ill, they didn't transmit to the rest of the community,” says Osterholm.

However, Osterholm says now that has changed, pointing to Minnesota where more than 740 schools have had cases of the UK variant and to Michigan where more young people are being hospitalized as cases rise.

Months ago, The British Medical Journal said there was “emerging evidence from Israel and Italy that more young children are being infected with new variants of COVID-19.”

Experts say now it is happening in the U.S., and Osterholm is questioning his own recommendation to send kids back for in-person learning.

"B.1.1.7 turns that on its head. These kids now are really major challenges in terms of how they transmit," says Osterholm.

As for the vaccines, Osterholm says, "We're not going to have nearly enough in the next six to eight weeks to get through this surge, and we're going to have to look at other avenues to do that just as every other country in the world who's had a B.1.1.7 surge has had to do."

Starting tomorrow in New York, anyone 16 and older can sign up to get vaccinated.

No vaccine has been approved yet for children younger than that.