The highly contagious strain of COVID-19 that originated in the UK is expected to become the dominant strain in the U.S., according to the Centers for Disease Control and Prevention. 

As the Washington Post reports, the CDC released a forecast last month predicting that the variant would become the primary strain in March. Researchers estimate the mutation is about 50 percent more transmissible than the common COVID strain. 

The variant is not known to cause a more severe illness, but an increase in COVID spread logically leads to more cases and therefore more deaths in the ongoing pandemic. This data is now being backed up by a new study from researchers that serves as a another sobering reminder of the importance of distributing vaccines quickly. 

“Our study shows that the U.S. is on a similar trajectory as other countries where B.1.1.7 rapidly became the dominant SARS-CoV-2 variant, requiring immediate and decisive action to minimize covid-19 morbidity and mortality,” authors of the new study posted on the preprint server MedRxiv wrote.

In light of this information, the CDC is not suggesting new restrictive measures, but encouraging people to continue to wear masks, stay home as much as possible, get tested, and social distance. 

“Increased SARS-CoV-2 transmission might threaten strained healthcare resources, require extended and more rigorous implementation of public health strategies, and increase the percentage of population immunity required for pandemic control,” the CDC wrote. “Taking measures to reduce transmission now can lessen the potential impact of B.1.1.7 and allow critical time to increase vaccination coverage.” 

There’s also a question about how mutations affect the efficacy of vaccines. Moderna and Pfizer are already creating booster shots to help combat new strains. 

Other variants, which include one from Brazil and two from South Africa, are also of concern for their potential in enhancing COVID-19 transmission. But the main focus has been on the UK strain known as B.1.1.7. 

“It is here, it’s got its hooks deep into this country, and it’s on its way to very quickly becoming the dominant lineage,” said the study’s co-author Michael Worobey, an evolutionary biologist at the University of Arizona.

The CDC forecasts that if the U.S. is able to ramp up vaccinations, new infections are expected to decline in the next few months. 

“There is reason to be concerned. We’re not out of the woods on this pandemic yet,” Jay C. Butler, the CDC deputy director for infectious diseases, said last month. “We need to continue to press ahead.”