Seven variants of the COVID-19 virus have been detected in the U.S., and all or some of them may contain mutations similar to the qualities exhibited by a strain of extra-contagious COVID-19 spreading in the U.K., a new study found.

The study, published Sunday on MedRxiv.org, found seven previously undiscovered variants of COVID-19 in U.S. patients, all of which are thought to have originated domestically, according to reporting in The New York Times.

The viruses also had mutations at the same part of their genes which determine how the virus enters human cells, which researchers told the Times could mean that the strains are more contagious in a manner similar to the strain blamed for the latest surge in cases in the U.K., though this hypothesis is unproven.

ADVERTISEMENT

“There’s clearly something going on with this mutation,” said Jeremy Kamil, the study’s co-author, who studies virology at Louisiana State University. “I think there’s a clear signature of an evolutionary benefit.”

The U.K. experienced a massive surge of new COVID-19 cases through December and January, causing the country to experience the highest rate of COVID-19 infections globally.

British officials have rolled out a massive vaccination program in response and declared over the weekend that 1 in 4 adults in the U.K. are now vaccinated.

Centers for Disease Control Director Rochelle WalenskyRochelle WalenskyWalensky: ‘We can’t let our guard down’ even though virus numbers are dropping Sunday shows – Trump acquittal in second impeachment trial reverberates CDC director says vaccinated teachers not a ‘prerequisite’ for schools to reopen MORE said in January that the U.K. variant had been detected in 26 U.S. states.

“The variants that have been identified recently seem to spread more easily, they’re more transmissible, which can lead to an increased number of cases and increase stress on our already taxed health care system,” Walensky said last month.