President-elect Joe Biden, Dr. Jill Biden sing ‘Happy Birthday’ to Dr. Anthony Fauci

President-elect Joe Biden and Dr. Jill Biden posted a sweet audio recording to Twitter singing "Happy Birthday" to Dr. Anthony Fauci, who turned 80 on Christmas Eve.

The pair wished the longtime director of the National Institute of Allergy and Infectious Diseases (NIAID) a happy birthday as he planned to celebrate both the Christmas holiday and his day of birth at home, according to an interview Fauci did with the Washington Post.

FILE - Democratic presidential nominee Joe Biden appears oh stage with his wife Dr. Jill Biden after delivering his acceptance speech on the fourth night of the Democratic National Convention from the Chase Center on Aug. 20, 2020 in Wilmington, Dela

Fauci said he normally celebrates his birthday and Christmas Eve with a traditional Italian dinner at his sister’s home in Alexandria, Virginia, but this year he’s had to change his plans, just as millions of Americans have amid the ongoing COVID-19 pandemic.

Fauci will stay home in Washington, D.C. with his wife of 35 years, Christine Grady — who is the chief of the bioethics department at the NIH Clinical Center. He opted to make a traditional Italian timpano dish while his three adult daughters, who are scattered across the country, watched remotely.

"It turned out perfectly," Fauci told the Post. "The pressure was really on. If I had messed it up and it had fallen apart out of the pot it would have been very embarrassing."

This week, Washington, D.C. Mayor Muriel Bowser proclaimed Thursday as "Dr. Anthony S. Fauci Day" in the nation's capital in honor of the country’s top infectious disease expert's birthday.

RELATED: Dr. Anthony Fauci celebrating 80th birthday, Christmas at home amid pandemic fight

Fauci, whose father lived to be 97, told the post that he’s worked every day since January, focused on fighting the coronavirus pandemic. He added that his days as a young doctor working night shifts at a big New York City hospital have helped him deal with the demands of his job years later.

"There is no option to get tired. There is no option to sit down and say ‘I’m sorry, I’ve had enough,’" he told the newspaper.

His milestone birthday comes just days after Fauci and other top officials publicly received their first dose of the Moderna coronavirus vaccine. Fauci said he wanted being vaccinated to serve as "a symbol to the rest of the country that I feel extreme confidence in the safety and efficacy of this vaccine.

FILE - Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, gives the thumbs up after receiving his first dose of the COVID-19 vaccine at the National Institutes of Health on December 22, 2020 in Bethesda, Marylan

Fauci has served under six presidencies and has spent much of his career fighting HIV/AIDS. He's been praised for his role in creating the President's Emergency Plan for AIDS Relief (PEPFAR), a program credited with saving millions of lives throughout the world, according to his NIAID biography.

Earlier in December, Biden asked Fauci to continue serving as the NIAID director as well as take on the role of chief medical adviser during his administration. Fauci "absolutely" accepted the offer, according to an interview he did on CNN.

Meanwhile, more than 1 million Americans have received the first rounds of COVID-19 vaccines. While the achievement is historic, health experts are warning the public of hard times ahead. Despite Moderna’s first rollout of vaccines and Pfizer-BioNTech’s promise of an additional 100 million doses, supplies are limited.

The U.S. Centers for Disease Control and Prevention advised Americans to remain vigilant and continue to avoid traveling. The CDC urged social distancing and wearing a mask.

The virus is responsible for infecting more than 18 million Americans and killing over 327,000, topping the global death toll list, with Brazil and India coming in at second and third.

FOX News and Kelly Taylor Hayes contributed to this report.