Osterholm, who served as a member of President Biden's COVID-19 transition advisory board, said the variants pose a significant problem despite underscoring that existing vaccines appear to be effective against them.
"I believe that, in some ways, we're almost in a new pandemic," Osterholm told "Fox News Sunday" host Chris Wallace. "The only good news is that the current vaccines are effective against this particular variant B.1.1.7."
B.1.1.7 is also known as the "British variant."
Scientists were concerned that the variant, which proved to spread far easier than the original coronavirus, might also render recently developed vaccines useless.
The vaccines have thus far proven effective at preventing infection, but Osterholm noted a number of other concerns that this particular variant raises.
One of the chief concerns Osterholm highlighted is that B.1.1.7 appears to be more virulent among children.
"They are now, as kids, getting infected at the same rate that adults do," Osterholm explained. "They're very effective at transmitting the virus."
"Just in Minnesota in the last two weeks we've had 749 schools with cases," he said.
Minnesota has 5,123 public and private PK-12 schools, according to GreatSchools.org, which would indicate that 14% of schools in the state have reported a coronavirus case.
Osterholm hasn't suggested locking down the country, mainly because of "the absolute resistance" to any kind of lockdown.
"There isn't a country in the world right now that is seeing a big increase in this B.1.1.7 that isn't locking down. We're the exception," Osterholm said, though he didn't touch on any comparison between the U.S. and Europe when it comes to vaccine distribution.
He referred to the variant as a "game changer" and insisted that the focus needs to be on getting through the next two to three months – as long as people continue to receive vaccinations and follow basic health guidelines, including hand-washing, mask-wearing and social distancing.
"Nobody wants to be the person to die three days before they were supposed to get their COVID shot. That’s what we’re trying to avoid right now."