By Betty Yu

SAN FRANCISCO (CBS SF) — International travelers prepared to fly out of SFO Sunday night as nations around the world raced to contain the new COVID variant. Starting Monday, the U.S. will ban travel from South Africa and seven other countries in the region.

Scientists are still trying to figure out how dangerous and contagious the Omicron strain is.

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“If someone who’s been infected with Delta is well protected from this and someone who is fully boosted is also well protected from this, that could be a pretty good backstop from this becoming really epidemic in the United States,” said former FDA Commissioner Dr. Scott Gottlieb.

But travelers at Oakland International were still wary of what the impact of the largest COVID strain might be.

“I’m actually very nervous about it. I’m going to Mexico and I’m going to be watching the news. If there’s anything that’s going to be a problem, I’m just going to come right back,” said Karen Schafer, who was traveling to Mexico.

Paris Arey and his wife are traveling to Ecaudor.

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“Quite frankly, it really hasn’t even, the COVID virus didn’t stop us from traveling. We traveled down to Mexico last year, and also to Ecador we took all the precautions, we found that they also took precautions there, so we felt safe. We’ve gotten our vaccines,” Paris said.

“We’ve been there before, the country’s following all the regulations and mandates, mask mandates. They’re vaccinated as much as we are, so we feel good about it,” said Lee Ann Britton-Arey.

Dr. Anthony Fauci said it will take time to have more definitive information on the transmissibility of omicron.

“People talking about lockdowns, people talking about that, let’s see what the information that we’re getting in real-time tells us and we’ll make decisions based on the science and the evidence, the way we always do,” said Fauci.

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The World Health Organization has warned against any overreaction until the variant is better understood.