Dr. Anthony Fauci told The Washington Post that his message for Christmas is to "tone things down," including gathering outdoors when possible, wearing a mask when not eating or drinking, and keeping gatherings to as few people as possible and within your household.

Fauci is not only celebrating Christmas on Thursday, but also his 80th birthday. And for the first time, Fauci won’t be with his daughters for the big day.

"This is the first time since the birth of my daughters, and they are now in their late 20s and early 30s, that we have not been together on Christmas Eve,” Fauci said. “I'm not alone in this feeling that kind of pain of separation from our loved ones.”

His milestone birthday was marked with a surprise Zoom party organized by his wife.

"I want to practice what I preach. I don't want to tell the country to do something that I'm not willing to do myself,” Fauci said. “I was just on a Zoom call with the girls ... I think I lost about a liter of fluid in tears, to be honest, with hearing their expressions of love and concern to me. But we ended it on a happy note because we know that sooner or later, very likely sooner, as we get into 2021 and things get better and vaccines help us, that this time next year we'll be back again with the Fauci family celebrating.”

ABC News’ Stephanie Ebbs contributed to this report.

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.