DENVER (AP) — The first reported U.S. case of the COVID-19 variant that’s been seen in the United Kingdom has been discovered in Colorado, Gov. Jared Polis announced Tuesday.

Today we discovered Colorado’s first case of the COVID-19 variant B.1.1.7, the same variant discovered in the UK.

The health and safety of Coloradans is our top priority and we will monitor this case, as well as all COVID-19 indicators, very closely. pic.twitter.com/fjyq7QhzBi

— Governor Jared Polis (@GovofCO) December 29, 2020

The coronavirus variant was found in a man in his 20s who is in isolation southeast of Denver and has no travel history, state health officials said.

The Colorado State Laboratory confirmed the virus variant, and the Centers for Disease Control and Prevention was notified.

Scientists in the U.K. believe the new virus variant is more contagious than previously identified strains of the SARS-CoV-2. The vaccines being given now are thought to be effective against the variant, Colorado health officials said in a news release.

Public health officials are investigating other potential cases and performing contract tracing to determine the spread of the variant throughout the state.

“There is a lot we don’t know about this new COVID-19 variant, but scientists in the United Kingdom are warning the world that it is significantly more contagious. The health and safety of Coloradans is our top priority, and we will closely monitor this case, as well as all COVID-19 indicators, very closely,” Polis said.

The discovery of the new variant lead the CDC to issue new rules on Christmas Day for travelers arriving to the U.S. from the U.K., requiring they show proof of a negative COVID-19 test.