Beginning Monday, all passengers aboard United flights from the United Kingdom will have to present proof of a negative COVID-19 test before departing for Newark Liberty International Airport
in New Jersey.

Gov. Phil Murphy said it’s meant to “strengthen existing travel protocols” as the U.K. discovers new variants of the virus.

New York Gov. Andrew Cuomo has enacted the same rule for U.K. flights arriving at New York City’s John F. Kennedy International Airport.

There’s no evidence the new variants are more deadly and it’s highly likely the vaccine will still work, experts said Wednesday at a virtual Q&A hosted by the World Health Organization.

ABC News' Aaron Katersky contributed to this report.

Over the last 24 hours, more than two Americans tested positive for COVID-19 every second, and two deaths reported every minute, according to ABC News’ analysis of data compiled by the COVID Tracking Project.

More Americans are now hospitalized with COVID-19 than ever before. There are 119,163 Americans currently hospitalized, marking the 19th day that the U.S. has hit a record high of current hospitalizations this month.

Current hospitalizations have increased by nearly 40% in the last month. The total number of patients hospitalized is now approximately double the spring and summer peaks in April and July.

Hospitalizations are on the rise in every region of the country except for the Midwest. Over 44,000 people are hospitalized in the South and over 30,500 people are hospitalized the West -- both record highs.

California has the most hospitalizations of any state with more than 19,000 hospitalized, followed by Texas, New York and Pennsylvania.

ABC News’ Arielle Mitropoulos contributed to this report.

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.