Countries around the world including the U.S. have imposed new travel restrictions this week as the World Health Organization met today to discuss a new and potentially highly transmissible COVID-19 variant, the newly named omicron.

First discovered in Botswana on Nov. 11, cases of variant B.1.1.529, now named omicron, were discovered in South Africa just three days later. More cases have now been identified spanning multiple continents. South Africa, Hong Kong, Israel and Belgium have all confirmed cases of the new variant, though U.S. authorities have not identified any cases inside the United States so far.

The new variant may pose a higher threat than the now-common delta variant due to a much higher number of mutations that could allow the virus to side-step vaccine-boosted immune systems.

“This variant has a large number of mutations, some of which are concerning,” a statement from the World Health Organization reads. “Preliminary evidence suggests an increased risk of reinfection with this variant.”

Tulio de Oliveira, Director of South Africa's Centre for Epidemic Response and Innovation echoed the WHO's concerns about the new strain. "This new variant is really worrisome at the mutational level," Oliveria said yesterday via Twitter. "In less than 2 weeks (omicron) now dominates all infections following a devastating delta wave in South Africa."

The U.S. now joins numerous other countries in banning travel to eight countries, including South Africa. The travel ban will not include U.S. citizens returning from those countries, though travelers will still have to provide a negative COVID-19 test before returning.

President Joe Biden ordered the ban today after a briefing with Dr. Anthony Fauci, chief medical advisor to the president of the United States, and other members of the U.S. COVID response team.

"As a precautionary measure until we have more information, I am ordering additional air-travel restrictions from South Africa and seven other countries," Biden said in a statement.

Biden implored Americans to get their booster shots or get vaccinated if they had not done so already, and challenged the global community to raise vaccination rates and donate vaccines to countries in need.

"The news about this new variant should make clearer than ever why this pandemic will not end until we have global vaccinations," Biden said. "The United States has already donated more vaccines to other countries than every other country combined. It is time for other countries to match America’s speed and generosity."

Dr. Eric Topol, founder and director of the Scripps Research Translational Institute in La Jolla, Calif., who recently gave an interview with the Mississippi Free Press, spoke with CNN about the new variant.

“It's the first variant we've seen since delta which raises such concern,” Topol said. “There's a lot of different mutations in the sequence and the rapidity that it's spreading in a province in South Africa as well as Botswana is concerning.”

Though many countries now have travel restrictions already in place, the WHO called for countries to avoid knee-jerk reactions to the new variant.

“At this point, implementing travel measures is being cautioned against," said Christian Lindmeier, Spokesperson for the WHO. “"The WHO recommends that countries continue to apply a risk-based and scientific approach when implementing travel measures."

Email Reporting Fellow Julian Mills at [email protected].