Coronavirus variantThe Centers for Disease Control and Prevention warned Friday that the highly transmissible coronavirus variant first discovered in the U.K. will likely become the dominant strain in the U.S. this March if more steps aren’t taken to mitigate the spread.

The state of play: Only about 76 people in a dozen states have been diagnosed with the the B.1.1.7 variant so far, according to the CDC, but experts warn there are likely more undetected cases. Although the variant is more contagious, it does not appear to be resistant to existing vaccines or cause more severe symptoms.

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Recent research by Public Health England found the B.1.1.7 variant is about 30%-50% more transmissible than other forms of the virus.

What they’re saying: “The modeled trajectory of this variant in the U.S. exhibits rapid growth in early 2021, becoming the predominant variant in March,” according to the CDC study published Friday.

“The increased transmissibility of the B.1.1.7 variant warrants rigorous implementation of public health strategies to reduce transmission and lessen the potential impact of B.1.1.7, buying critical time to increase vaccination coverage,” the study added.

“Currently, there is no known difference in clinical outcomes associated with the described SARS-CoV-2 variants; however, a higher rate of transmission will lead to more cases, increasing the number of persons overall who need clinical care, exacerbating the burden on an already strained health care system, and resulting in more deaths.”

The big picture: Viruses mutate, often without impacting the severity of disease or how the virus spreads. But sometimes mutations are consequential for public health and scientists say it’s important to monitor them, Axios’ Marisa Fernandez reports.

Officials worldwide are tracking the SARS-CoV-2 variants, including the B.1.1.7 variant, the 501.V2 variant in South Africa and a newly discovered variant in Brazil.

Pfizer and Moderna are in the process of testing their vaccines against the variants. The pharmaceutical companies said Thursday the mutation N501Y found in both variants B.1.1.7 and 501.V2 was tested against their vaccine and found “no reduction in neutralization activity against the virus.”

But there are multiple mutations and more studies are underway.

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