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LOS ANGELES - Nearly 2.5 million people were screened by Transportation Security Administration (TSA) agents on Sunday, Nov. 28, the most since the pandemic began according to the agency.
TSA tweeted on Monday that travel volume for the 10 days leading up to Nov. 28 was 20.9 million people, roughly 89% of pre-pandemic levels.
TSA officers screened 2,451,300 individuals on Sunday, a new pandemic high. For the 5-day holiday weekend Wed thru Sun, volume was 10.1M, according to the TSA.
The high volume of holiday travel is a cause for concern for health experts raising alarms over the newly discovered coronavirus omicron variant.
This past weekend, President Joe Biden urged Americans to get vaccinated and to receive a booster shot amid worries about the highly transmissible new variant — saying the new strain is a "cause for concern, not a cause for panic."
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Biden, who gave remarks at the White House, emphasized the importance of vaccination to protect against all variants of the COVID-19 virus and the urgency of vaccinating the roughly 80 million Americans aged 5 and up who haven't received a shot. But Biden said he does not anticipate the need for any new virus-related restrictions, beyond last week's move to restrict travel from South Africa and seven other countries in the region, which went into effect on Monday.
"I expect the new normal to be, everyone ends up getting vaccinated and the booster shot, so we reduce the number of people who aren't protected to such a low degree that we're not seeing the spread of these viruses," he said, noting that there won't be a need for lockdown measures.
The president also praised South African scientists for acting fast to identify the new variant, saying the world will fight it "with scientific and knowledgable actions and speed, not chaos and confusion."
RELATED: COVID-19 vaccine makers exploring if omicron versions of shots are needed
Dr. Anthony Fauci, the nation's top infectious disease expert and Biden's leading COVID-19 adviser, said earlier Monday that there were still no cases of the variant identified in the U.S. but that it was "inevitable" that it would make its way into the country eventually.
On Nov. 26, a World Health Organization panel named the latest variant "omicron" and classified it as a highly transmissible virus of concern, the same category that includes the predominant delta variant — which is still a scourge driving higher cases of sickness and death in Europe and parts of the U.S.
Omicron’s actual risks are not fully understood yet. But early evidence suggests it carries an increased risk of reinfection compared with other highly transmissible variants, the WHO said. That means people who contracted COVID-19 and recovered could be subject to catching it again. It could take weeks to know if current vaccines are less effective against it.
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Medical experts, including the WHO, warned against any overreaction before the variant was thoroughly studied. But a jittery world feared the worst after the tenacious virus triggered a pandemic that has killed more than 5 million people around the globe.
That being said, health officials are calling for travelers to be as careful as possible this holiday season.
With the emergence of the new variant and the pandemic being far from over, is travel safe during the pandemic during the holidays?
It depends. It can be safe if you’re fully vaccinated against COVID-19, but officials say people who haven’t gotten the shots should delay travel.
Regardless of vaccination status, all travelers should keep taking precautions like avoiding indoor, unmasked crowds, says Dr. Keith Armitage, an infectious disease expert at Case Western Reserve University.
"The delta variant has really brought us back to an earlier time in the pandemic," he said.
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The U.S. Centers for Disease Control and Prevention said not to travel if you’re sick, or if you tested positive for COVID-19.
The CDC recommends isolating at home for 14 days after your last contact with a person who has COVID-19. Symptoms to look out for include shortness of breath, cough, or fever.
Additionally, health experts say your isolation period isn’t necessarily over after those 14 days— even if you’re fully vaccinated. Unvaccinated people who decide to travel should get a COVID-19 test one to three days before travel and three to five days after returning.
All travelers must still wear masks on trains, planes and other indoor public transportation areas, the agency says.
Airlines say plane cabins are low risk since they have good air circulation and filtration. However, there is no requirement for vaccination or testing before domestic flights, and passengers can remove their face masks while eating or drinking.
Hotels aren’t risky for the vaccinated as long as they wear masks around strangers, Armitage says. More fraught are family gatherings with unvaccinated individuals, particularly for those who are older or have health problems.
Health experts suggest looking at the case levels and masking rules in the place you are visiting before you travel.
This story was reported from Los Angeles. Chris Williams, Kelly Hayes and The Associated Press contributed.