Colorado reports first known U.S. case of new coronavirus variant

Colorado's health department discovered the new variant of the coronavirus that may be more transmissible, Gov. Jared Polis announced on Tuesday.

Why it matters: It's the first known U.S. case of the variant, which was initially discovered in the United Kingdom.

• A non-peer reviewed study by the Centre for Mathematical Modelling of Infectious Diseases at the London School of Hygiene and Tropical Medicine found that the variant is 56% more transmissible than other strains.
• The British government previously warned that a new variant could be up to 70% more transmissible.

Of note: There is thus far no evidence that the new variant is more deadly — only that it appears more transmissible. There is also no evidence that COVID-19 vaccines will be less effective against the new variant.

What they're saying: "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," Polis tweeted Tuesday.

• According to Polis’ office, the case involves a man in his 20s who has no travel history.
• The man is currently in isolation, and public health officials are doing a “thorough investigation,” the governor’s office added.

The big picture: Dozens of countries banned travel from the U.K. after it discovered the variant.

• Japan announced last week that it would temporarily ban non-resident foreign nationals from entering the country starting on Dec. 28 after it discovered its first case of the new variant.

Go deeper: What you need to know about the coronavirus mutation