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.

Dr. Anthony Fauci, chief medical adviser to U.S. President Joe Biden and the nation's leading infectious disease expert, said Americans can expect to see more COVID-19 vaccine doses available throughout the country in the coming weeks.

"As we get into February, March and April, we're going to see an escalation of availability of doses that we may have not had a week or two or three ago," Fauci, who is also the director of the National Institute of Allergy and Infectious Diseases, told ABC News chief anchor George Stephanopoulos Thursday on "Good Morning America."

Although COVID-19 data is starting to show some promising trends, Fauci said the U.S. outbreak is "still a very serious situation."

"If you look throughout the country, the dynamics of the outbreak are a little bit unstable," he noted, "even though for the most part we're seeing general trends, seven-day trends of cases going down and ultimately, hopefully, hospitalizations and deaths."

When asked about reopening schools safely, Fauci said COVID-19 transmission rates in schools actually appear to be less than in communities when the schools have the resources and protection they need.

"So if you have a situation where you have dynamics of a viral spread in a community, it's less likely that the children who are in the school -- if we do things right, it's less likely that they're going to get infected," he said. "Obviously we want to get the teachers vaccinated, we want to make sure they have the resources to do it correctly. But when you look at the history of how this virus is moving in schools, it seems to be less spreading there than it is in the community."

Fauci also expressed concern over the new, more contagious variant of the novel coronavirus that was first identified in South Africa and has since spread to dozens of other nations, including the United States.

"The one in South Africa, George, troubles me," he said, explaining that lab experiments show the neutralizing antibodies induced by existing COVID-19 vaccines are "diminished by multifold" when tested against the South Africa variant, called B1351.

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

However, scientists are already working on vaccines that will specifically target the South Africa strain, 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."