Experts are concerned the omicron variant might be more transmissible or may lead to more severe illness, and its high number of mutations have some concerned it could evade vaccines, but Fauci emphasized that more information is necessary.

"That's the reason for doing that, not any reason to panic, but we want to give us some time to really fill in the blanks of what we don't know right now," the chief medical advisor to President Biden said.

"It may not turn out that way, but you really want to be ahead of it, and that's the reason why we're doing what we're doing.".

He said that the threat of this variant, or any other variant, should also encourage people to get vaccinated.

"It is absolutely essential that unvaccinated people get vaccinated and that vaccinated people get boosters," Fauci said

You don't want people to panic, but you want to know that we're doing everything we can to stay ahead of this."