An adult in South Carolina’s Lowcountry region has become the state’s first confirmed case of the United Kingdom COVID-19 variant, South Carolina’s Department of Health and Environmental Control said.

The person "has an international travel history," the department said.

The U.S. has confirmed at least 434 cases of the B.1.1.7 U.K. variant across 30 states, South Carolina officials said.

"Experts agree that existing vaccines work to protect us from this variant, even if we don’t know just how effective they are," the South Carolina officials said. "At this time, there’s no conclusive evidence to prove that the B.1.1.7 variant causes more severe illness."

ABC News’ Josh Hoyos contributed to this report.

The Coachella Valley Music and Arts and Stagecoach Country Music festivals, set for April, were canceled on Friday by Dr. Cameron Kaiser, health officer for Riverside County, California.

Riverside County’s positivity rate stands at 20%. The county has 0% bed availability in its intensive care units.

January has been the deadliest month since the pandemic began, with 90,844 total deaths, according to data compiled by Johns Hopkins University.

The U.S. coronavirus death toll stands at 436,810 -- with the Center for Disease Control and Prevention projecting that more than 77,000 deaths could be reported by Feb. 20.

California is now the second U.S. state with known detection of the Brazil P.1 variant.

Minnesota health officials confirmed earlier this week the nation's first known COVID-19 case associated with the variant.

Inside Stanford's Clinical Virology Laboratory, Dr. Benjamin Pinsky and his team found two strains of the virus: the Brazil strain and the U.K. strain, KGO reported Saturday morning.

"It's in about 17% of the samples that we've sequenced," Pinsky told KGO.

The United States’ first known cases of the South Africa variant of the novel coronavirus have been confirmed in two people in South Carolina, according to the South Carolina Department of Health and Environmental Control.

"There is no known travel history and no connection between these two cases," the department said in a statement Thursday.

Both cases are among adults, one who is from the Lowcountry region and another who is from the Pee Dee region, according to the department.

The U.S. Centers for Disease Control and Prevention said it's aware of the cases and it "recommends that people avoid travel at this time."

The so-called B1351 variant, first identified in South Africa, has been detected in more than 30 countries, according to the South Carolina Department of Health and Environmental Control.

"Experts agree that existing vaccines work to protect us from this variant, even if we don’t know precisely how effective they are," the department said. "At this time, there’s no evidence to suggest that the B.1.351 variant causes more severe illness."

During an interview Thursday on ABC's "Good Morning America," Dr. Anthony Fauci, chief medical adviser to U.S. President Joe Biden and the nation's leading infectious disease expert, said the South Africa variant "troubles" him.

Fauci said lab experiments show the neutralizing antibodies induced by existing COVID-19 vaccines are "diminished by multifold" when tested against the B1351 variant

"It's still within the range of what you would predict to be protective," he said, "but I take no great comfort in that."

However, scientists are already working on vaccines that will specifically target the South Africa variant, according to Fauci.

"May not be necessary," he said, "but if it is we'll already be on the road to be able to give people a boost that directs against the South African isolate."