DAVIS (CBS13/AP) – Yolo County now has its first known case of the Omicron variant of COVID-19.

The announcement was made Thursday by a county spokesperson. He didn’t say when or where exactly the variant was detected, only that it was found during Healthy Davis Together and the UC Davis Genome Center’s free testing operations.

READ MORE: Man Arrested In South Sacramento After ShotSpotter Activation

Despite there not being a lot of information about the variant, Yolo County Public Health Officer Dr. Aimee Sisson says the virus could spread quickly and urges people to get vaccinated, get a booster shot if eligible and wear a mask.

READ MORE: Verizon Delays 5G Rollout Again Amid Safety Concerns At Airports

“The detection of the potentially highly transmissible Omicron variant is concerning, especially with more people traveling and visiting with friends and family for the holidays,” said Dr. Aimee Sisson, Yolo County Public Health Officer. “There is still a lot we don’t know about the Omicron variant, but this detection is a reminder that we must remain vigilant in using the tools we have to protect ourselves against Delta and Omicron, including vaccination, boosters, testing and following local guidance on mask wearing.”

MORE NEWS: Woman Charged In 'Largest EDD Fraud Scheme' In Sacramento County

New cases of COVID-19 in the U.S. climbed from an average of nearly 95,000 a day on Nov. 22 to almost 119,000 a day this week, and hospitalizations are up 25% from a month ago. The increases are due almost entirely to the delta variant, though omicron has been detected in about 20 states and is sure to spread even more.

Since the pandemic started, California has confirmed just over 4,861,352 cases and nearly 74,432 deaths.

(© Copyright 2021 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)