New COVID test requirement for all international air travelers

New travel restrictions were in effect Monday for all international air travelers in an effort to combat the omicron variant of the coronavirus.

The Centers for Disease Control and Prevention requires that all air travelers regardless of citizenship or vaccination status show a negative pre-departure COVID-19 viral test taken the day before boarding their flight to the United States.

Up until the change, only unvaccinated travelers had one day to show a negative test prior to departure, and vaccinated travelers had three days.

The reduced time frame was intended to be an added degree of protection and help reduce the spread of the variant that was first identified in South Africa, said the White House.

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RELATED: Connecticut reports first omicron case; may be tied to NYC

The variant lead to a dramatic spike in patients but severe cases had not been reported leading some health officials to believe the variant may not be as powerful as the current dominant strain known as delta.

Laboratory test results and real-world surveillance to determine whether the omicron variant of the virus that causes COVID-19 is more resistant to current antibody treatments and vaccines could take weeks. But researchers are concerned about changes to the spike protein, which Dr. Anthony Fauci calls "the business end of the virus."

RELATED: Gov. Hochul: Three new Omicron variant cases found in NY

"And these mutations have been associated with increased transmissibility, and immune evasion," Fauci said. 

There are at least 15 states reporting cases of the omicron variant including eight in New York, one in New Jersey and one in Connecticut.