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.

The New York City health care provider under investigation for allegedly misappropriating the Moderna coronavirus vaccine, told ABC News it will return its vials to the state Health Department.

The New York State Department of Health is currently probing ParCare, which has offices in Brooklyn, to determine if it misused what was an approved allocation toward members of the public not yet prioritized under current New York guidelines.

Under the current state rules, only medical workers, first responders and nursing home staff members are allowed to receive any coronavirus vaccine. Other groups will follow in future rounds.

ParCare touted the vaccine on its social media pages with a flyer that claimed the vaccines would be available on a "first come, first serve basis."

"We have set up a special system where you can reserve your slot. This will enable you to receive the vaccine as soon as it arrives to the center," the flyer said.

The flyer also claimed that the vaccines were only for people who were "elderly," "high risk" or "underlying conditions."

New York state police and other investigators were at the ParCare location in Borough Park on Saturday night.

A spokesman for ParCare told ABC News Sunday evening that it is cooperating with the state investigation and will return its unused vials.

ParCare received 2,300 doses of the Moderna vaccine, and 869 of those doses have already been administered, according to the spokesperson.

"ParCare followed all NYS DOH procedures for obtaining the Moderna vaccine and was approved by NYS DOH for distribution and by CDC as a network site. As a result, we have properly received the vaccines and have provided the documentation regarding the proper receipt of the vaccines to the NYS DOH," the spokesperson told ABC News.

With regards to the patients who received their first shot, ParCare said it will be "working with the state to ensure that we provide the second dose for our patients."

-ABC News' Sasha Pezenik and Aaron Katersky contributed to this report