Though vaccines are shown to be effective against these variants, experts warn it is crucial to get ahead of them with widespread immunization.

If the virus continues to spread, it has an increased chance of spawning variants that are even more contagious, Offit said.

"When a virus is more contagious, you need to have a higher percentage of the population that is protected, immunized, if you're going to stop the spread," he added.

As of Monday, 52.5% of Americans had received at least one dose of vaccine, but only 43.7% were fully vaccinated, according to data from the US Centers for Disease Control and Prevention.

Offit said by the winter, when the virus is likely to surge again, the US will need to get the number of fully vaccinated up to 80% or higher to protect the population.

The good news, Offit said, is that although the spread of more contagious variants may be less inhibited by vaccines, the level of protection still appears to be high.

"I think that vaccines will keep you out of the hospital, will keep you out of the ICU, and will keep you from dying," Offit said.