Leaders in Britain and other nations on Friday reacted with alarm over a new COVID-19 variant detected in South Africa, which a top U.K. health official described as the "most significant" variant identified yet.
The discovery of the variant has already prompted several European and Asian nations to suspend flights from southern Africa as health authorities investigate how the variant may interact with current COVID-19 vaccines.
"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 Jenny Harries, chief executive of the UK Health Security Agency.
"The results of these investigations will determine what public health actions may limit the impact of B.1.1.529," the official added, referring to the variant.
The first genomes of the variant were uploaded to an international database Monday, and officials said genomes have now been uploaded from South Africa, Hong Kong and Botswana, though officials have not yet determined the extent of the spread.
British officials said Friday that no cases had been identified in the U.K.
The UK Health Security Agency said the variant has "potentially biologically significant mutations which may change the behaviour of the virus with regards to immune escape, transmissibility or susceptibility to treatments," though it noted that has not been proven.
Officials cited more mutations in the spike protein of the virus and the U.K. has labeled it a "variant under investigation."
"We are taking precautionary action to protect public health and the progress of our vaccine rollout at a critical moment as we enter winter, and we are monitoring the situation closely," U.K. Secretary of State for Health and Social Care Sajid Javid said in a statement.
The World Health Organization (WHO) announced that it would hold a special meeting Friday to discuss the new variant.
"We're calling a special meeting to discuss this, not to cause alarm, but just because we have this system in place. We can bring these scientists together and discuss ‘What does it mean?’ and also kind of set the timeline for how long it will take for us to get those answers," said Maria Van Kerkhove, the WHO's COVID-19 technical lead.
The U.K. has barred travel from six African countries starting Friday: South Africa, Botswana, Lesotho, Eswatini, Zimbabwe and Namibia. Other countries such as France, Italy, Israel, Japan and Singapore have also moved to limit travel.