Infectious Disease Expert Warns ‘We’re Not Done With This Virus At All’

But Osterholm said more localized surges could occur if the highly transmissible Delta variant takes hold in the U.S., where it is now quickly spreading.

The variant first identified in India has already become the dominant strain of the virus in the United Kingdom, where rising cases have forced the delay of easing lockdown restrictions.

Rochelle Walensky, director of the Centers for Disease Control and Prevention, said Friday that the Delta variant will “probably” become the most dominant in America. Osterholm agreed, noting its ability to evade the immunity provided by a single dose of one of the two-dose vaccines.

“We have over 100 counties in this country that have had less than 20% of their population vaccinated,” Osterholm told CNN’s Harlow on Friday in a video shared online by Mediaite. “We have states where we’re well below 40% with even a single dose of vaccine in people.”

“So we have a lot of susceptible people out there yet that have been not vaccinated, that, for example, should this Delta variant take over, we’re going to see local and regional surges that are substantial,” he continued.

“I think this is all the more reason why we have to know that we’re not done with the virus yet,” Osterholm added. “We’re surely farther along in this country than other places but we still need to get people vaccinated. And as you know, things have slowed down dramatically in terms of new people getting vaccinated.”

Osterholm recalled similar fears over the Alpha variant, which was first identified in the U.K. and then spread across Europe in January and February. A predicted devastating surge in the U.S. never materialized, though.

“It did become the dominant variant, but we didn’t see the big increase in cases,” Osterholm said. “So, I’ve obviously had a note of caution here with regard to the Delta variant, this new one we’re talking about.”

“Maybe the same thing will happen, but maybe it won’t,” he admitted. “And we have to be, in our business, prepared for the ‘Maybe it will happen like it did in England.’”