Another 16,400 to 27,600 Americans are expected to die from COVID-19 by Jan. 16, the Centers for Disease Control and Prevention said, citing its national ensemble forecast from 36 modeling groups.

That would bring the total COVID-19 death toll in the U.S. to between 378,000 and 419,000.

At least 326,495 Americans have died so far, according to data compiled by Johns Hopkins University.

ABC News’ Ahmad Hemingway contributed to this report.

The TSA screened 1,191,123 people at airport checkpoints nationwide on Wednesday, the highest single day total since the pandemic started, despite the Centers for Disease Control and Prevention advising Americans against traveling for the holidays.

More than 6.3 million passengers have been screened since Dec. 18 .

ABC News’ Sam Sweeney and Ahmad Hemingway contributed to this report.

California now has more than 2 million confirmed cases of coronavirus since the start of the pandemic -- the first state to report the grim milestone.

The state has at least 2,010,004 diagnosed cases and 23,651 deaths, according to data compiled by Johns Hopkins University.

Grant Shapps, the United Kingdom's transportation secretary tweeted that all flights to and from South Africa will be halted starting 9 a.m. Thursday, after a new coronavirus mutation was discovered in that country.

"British & Irish Nationals, visa holders and permanent residents arriving from South Africa will be able to enter but are required to self-isolate for ten days along with their household," he tweeted.

South African nationals won't be allowed to enter the U.K. until the ban is lifted, Shapps said.

An increasing number of children are being infected with multisystem inflammatory syndrome in children (MIS-C), according to a statement Saturday relased by Los Angeles County Board of Supervisors Chair Hilda L. Solis, supervisor to the First District.

"It is heartbreaking that every day, more than 14,000 Los Angeles County residents are testing positive for COVID-19. It is even more painful to see an increasing number of children being infected by MISC-C. There is a misconception that COVID-19 only impacts those who are older or those with underlying health conditions. At this point in the crisis, we can say for certain that COVID-19 causes severe consequences in people of all ages, including children, and even without underlying health conditions. In Los Angeles County, the Latinx community is bearing the brunt of COVID-19 and MISC-C cases," the statement read.

There have been 51 total cases of MIS-C in children, including one child death. All 51 children with MIS-C were hospitalized and nearly 50% of the children were treated in the intensive care unit. Of the children with MIS-C, 31% were under the age of 5 years old, 38% were between the ages of 5 and 11 years old, and 31% were between the ages of 12 and 20 years old. Latinx children account for nearly 73% of the reported cases, according to the statement.

Experts say the inflammatory syndrome resembles toxic shock syndrome and Kawasaki disease, itself a rare inflammatory disease typically affecting children under the age of 5, and has the potential to be deadly.

-ABC News' Matthew Fuhrman, Olivia Rubin and Soo Rin Kim