First confirmed case of omicron variant detected in United States

The California and San Francisco Departments of Public Health have confirmed the first case of the omicron variant in the United States in an individual in California who was fully vaccinated against COVID-19 and returned Nov. 22 from South Africa, the Centers for Disease Control and Prevention announced today. The individual had mild symptoms that are improving and is self-quarantining. All of the individual's close contacts have been contacted and tested negative, CDC said.

The World Health Organization Nov. 24 named Omicron a new variant of concern. The variant was first reported in South Africa. President Biden has ordered additional air travel restrictions for travelers to the U.S. from South Africa and seven other countries in Africa, which took effect Nov. 29.

"CDC has been actively monitoring and preparing for this variant, and we will continue to work diligently with other U.S. and global public health and industry partners to learn more," the agency said. It said the emergence of the new variant "further emphasizes the importance of vaccination, boosters, and general prevention strategies" to protect against COVID-19.