WASHINGTON (Reuters] – The United States won’t impose any further restrictions on the Omicron COVID-19 version, the country’s highest infectious disease officer said Monday. It was a week since a ban on travel from some countries in southern Africa had been lifted.

According to Dr. Anthony Fauci who spoke to Joe Biden late Monday night, officials had been preparing for the U.S.’s first confirmed case, but vaccines remain a key tool to reduce its effects.

A U.S. ban on travel from 8 southern African countries prevented most people from arriving in the United States hours earlier. This was done to reduce transmission and allow experts to evaluate Omicron’s severity, transmissibility, and effect on vaccines.

Asked if other curbs were imminent, Fauci told ABC News’ “Good Morning America” program: “I don’t think so at all.”

The pandemic caused a large part of the United States to shut down at the start of 2020.

Biden will give public remarks at 11:45 AM on the administration’s response. ET (1645 GMT), following Biden’s meeting with Fauci (and the rest of his COVID-19 group).

Fauci and U.S. officials in health on Monday stated that they anticipate the arrival of this variant and encouraged more Americans to be vaccinated.

Fauci said that the “Obviously we’re on High Alert” and also served as Biden’s chief physician adviser to ABC News. “It is inevitable that it will spread rapidly sooner or later,” Fauci said to ABC News.

Dr. Francis Collins, Director of the National Institutes of Health said that vaccines had so far been shown to be effective against COVID-19 variants. Officials hope this will hold true for Omicron vaccines as manufacturers rush to test them.

Collins stated that “there’s cause to be quite optimistic here,” in an interview with MSNBC.