Dr. Anthony Fauci says the country is back in a precarious situation, with daily COVID-19 case averages increasing in the past few weeks — signaling a potential surge that could mimic what is happening in Europe.

Throughout the pandemic, the U.S. has regularly lagged a few weeks behind Europe and could continue to follow suit, Fauci told Yahoo Finance. Getting Americans vaccinated is key in preventing another surge, he said.

"I believe that the vaccine will actually have a major impact on preventing us from having a classical surge that we've seen before, but we can't be overconfident, which is one of the reasons why we keep saying over and over again, let's not declare victory prematurely," Fauci said.

The chief medical advisor to President Joe Biden and director of the National Institute of Allergy and Infectious Diseases (NIAID) said he hopes that vaccines hold any major surge at bay.

"It really is kind of a race between the implementation of the vaccines and the danger, or not, of there being a bonafide surge. Hopefully, the protection that's afforded to the community, by the vaccinations will blunt any surge that is reminiscent of the previous surges that we've had," he said.

"If the country manages to reduce daily cases and get a majority of people vaccinated, "there will come a time, reasonably soon ... that you're going to see a greater diminution in the number of cases and a greater freedom and flexibility of what people can do," Fauci said.

But the threat of vaccine hesitancy and aggressive re-openings spurred by COVID fatigue loom large, and could elongate the time that the U.S. recovers from the pandemic.

The federal government was repeatedly criticized in 2020 for not establishing federal mandates to guide state re-openings and testing needs. But the new administration implemented national masking mandates in federal buildings and for public transportation.

Health experts have long wanted more direct guidance, as with the CDC's recent travel and gathering guidelines for fully vaccinated individuals. But the Biden administration is stopping short of broader-reaching mandates and things like vaccine passports.

"I don't believe that's going to change — that they do not want to dictate at the federal level, things that locally could be perceived as being discriminatory or potentially punitive," Fauci said.

Still learning about the virus

Fauci has repeatedly said at White House COVID-19 Response Team briefings that the U.S. is likely to remove mask mandates after reaching "herd immunity," which is when a majority of eligible adults and kids are fully vaccinated, and that it's likely that masks could be recommended into 2022.