Dr. Anthony Fauci says it could be at least two weeks before we know more definitive information about the omicron coronavirus variant.

However, the United States started to restrict travel for non-U.S. citizens from South Africa and seven other countries on Monday.

The move comes as the Biden administration seeks to assure Americans that they are moving swiftly to try to contain the new threat.

Biden said the new variant "is a cause for concern, but not a cause for panic."

Chief of Infectious Diseases at Northwell Health Dr. Bruce Farber agrees that it's a time to be proactive, but not to panic.

"What we don't know is the severity of illness that it causes," Farber says. "We don't know how good immunity that we have is going to be against this."

Biden is asking Americans to mask up in public settings regardless of vaccination status.

The president met with his COVID-19 response team as experts across the world are trying to figure out the severity of the variant.

At least a dozen countries have reported cases of the omicron variant, and many are shutting down their borders.

Experts say the best way to protect yourself is to get the vaccination, a booster and to continue wearing masks and social distancing.

Biden says he will put out a detailed strategy on Thursday to fight the virus this winter without shutdown or lockdowns, but with widespread vaccinations, boosters, testing and more.

"I mean I just think this is going to continue for a long time," says Glen Cove resident Patricia Basile. "A virus just mutates into different variants, and it's just gonna keep happening."

Moderna, Pfizer-BioNTech and Johnson & Johnson say they are planning to test an artificial version of the new variant against their vaccines in case they need to be tweaked.

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