CNBC's Meg Tirrell reports on the latest data from the omicron covid variant, which the World Health Organization has labeled a "variant of concern." For access to live and exclusive video from CNBC subscribe to CNBC PRO: https://cnb.cx/2NGeIvi The World Health Organization on Friday labeled a new heavily mutated strain of Covid-19 a variant of concern. “This variant has a large number of mutations, some of which are concerning,” the WHO said in a statement released Friday. “Preliminary evidence suggests an increased risk of reinfection with this variant, as compared to other VOCs.” The variant, first known as B.1.1.529 and now named omicron, has been detected in small numbers in South Africa, WHO officials said. However, the number of omicron cases “appears to be increasing” in almost all of South Africa’s provinces, the WHO reported on Friday. The omicron variant has since been found in the U.K., Israel, Belgium, the Netherlands, and Hong Kong. Here’s what we know so far: Multiple mutations South African scientist Tulio de Oliveira said in a media briefing held by the South Africa Department of Health on Thursday that the variant contains a “unique constellation” of more than 30 mutations to the spike protein, the component of the virus that binds to cells. This is significantly more than those of the delta variant. Many of these mutations are linked to increased antibody resistance, which may affect how the virus behaves with regard to vaccines, treatments and transmissibility, health officials have said. De Oliveira said the variant contains around 50 mutations in total. The receptor binding domain, the part of the virus that first makes contact with cells, has 10 mutations, far greater than just two for the delta Covid variant, which spread rapidly earlier this year to become the dominant strain worldwide. This level of mutation means it’s possible that it came from a single patient who could not clear the virus, giving it the chance to genetically evolve. The same hypothesis was proposed for the alpha Covid variant. Maria Van Kerkhove, the WHO’s technical lead on Covid-19, said in a livestreamed Q&A on Thursday that scientists “don’t know very much about this yet” and that it would take a few weeks to gain a full picture of how the variant reacts to existing vaccines. ‘Most significant variant’ to date The U.K. immediately moved to ban flights from South Africa, Lesotho, Botswana, Namibia, Eswatini and Zimbabwe from noon Friday to 4 a.m. local time Sunday. The U.K. Health Security Agency is investigating the variant, which Health Secretary Sajid Javid said is “potentially concerning.” No cases have yet been identified in the U.K., and Javid emphasized that although more data is needed at this early stage, the government had opted to take precautions. “This is the most significant variant we have encountered to date and urgent research is underway to learn more about its transmissibility, severity and vaccine-susceptibility,” said U.K. HSA Chief Executive Jenny Harries. Israel has also barred travel to several southern African nations over the new variant, as well as Singapore and other nations. Israel has reported one case of the new variant in a traveler returning from Malawi. Israeli Prime Minister Naftali Bennett met with health experts Friday to discuss the country’s response, which could reportedly include declaring a state of emergency. Belgium on Friday afternoon became the first European country to report a case of the B.1.1.529 variant. » Subscribe to CNBC TV: https://cnb.cx/SubscribeCNBCtelevision » Subscribe to CNBC: https://cnb.cx/SubscribeCNBC » Subscribe to CNBC Classic: https://cnb.cx/SubscribeCNBCclassic Turn to CNBC TV for the latest stock market news and analysis. From market futures to live price updates CNBC is the leader in business news worldwide. The News with Shepard Smith is CNBC’s daily news podcast providing deep, non-partisan coverage and perspective on the day’s most important stories. Available to listen by 8:30pm ET / 5:30pm PT daily beginning September 30: https://www.cnbc.com/2020/09/29/the-news-with-shepard-smith-podcast.html?__source=youtube%7Cshepsmith%7Cpodcast Connect with CNBC News Online Get the latest news: http://www.cnbc.com/ Follow CNBC on LinkedIn: https://cnb.cx/LinkedInCNBC Follow CNBC News on Facebook: https://cnb.cx/LikeCNBC Follow CNBC News on Twitter: https://cnb.cx/FollowCNBC Follow CNBC News on Instagram: https://cnb.cx/InstagramCNBC https://www.cnbc.com/select/best-credit-cards/ #CNBC #CNBCTV