Trump-Biden transition: Attorney Sidney Powell back at White House Sunday

In November 1972, Joe Biden made headlines as the 29-year-old lawyer who pulled off an upset win against Sen. Caleb Boggs to represent Delaware in the Senate -- one of the youngest people ever elected to the body. But it was a different headline a month after the election that would forever change his life: "Biden's wife, child killed in car crash."

"I was down in Washington hiring staff and I got a phone call from a first responder. They put a pretty young woman on the phone. She was so nervous, she said, 'You gotta come home. There's been an accident. A tractor trailer hit your wife and your three children while they were shopping,'" Biden recalled at a campaign event in Newton, Iowa, last August.

"My wife was killed and my daughter was killed," he continued. "And my two boys, but for the jaws of life, and a rescue crew saving their life, would not have been around either."

Friday morning, on the 48th anniversary of the accident, the president-elect refrained from public events, instead visiting the graves of his late wife, Neilia, and daughter, Naomi, at Brandywine Roman Catholic Church with his wife, Jill, near his home in Wilmington, Delaware.

The anniversary comes, as it did in 1972, as Biden is preparing for a new role in public life -- this time the presidency. The role caps off a lifetime in politics that almost ended before it began. Biden had initially decided to stay in the Senate for only six months following his wife and daughter's deaths and in order to care for his injured sons.

Despite his initial unwillingness to serve, Biden remained in the Senate and public life, turning his grief into a way to connect with others through empathy -- a trait that has perhaps most defined his career.

-ABC News' Molly Nagle

Biden and Vice President-elect Kamala Harris will introduce key nominees and appointees for their climate and energy team Saturday in Wilmington, Delaware.

The nominees and appointees attending the event will include secretary of interior nominee Rep. Deb Haaland, D-N.M.; secretary of energy nominee former Michigan Gov. Jennifer Granholm; E.P.A. administrator nominee Michael Regan; Chair of the Council on Environmental Quality nominee Brenda Mallory; national climate adviser appointee Gina McCarthy and deputy national climate adviser Ali Zaidi.

Asked whether he will join with other House Republicans to formally object to the certification of the Electoral College results on Jan. 6, House Minority Leader Kevin McCarthy, R-Calif., laughed and told reporters, "We'll watch and see," per the pool reporter on Capitol Hill. 

McCarthy hasn't formally taken a position on the long-shot effort, which still lacks Senate Republican support needed to force debate and vote on the results of the election, nor has he recognized Biden as the president-elect.

The Electoral College affirmed Biden's victory on Monday without any faithless electors. Trump won 232 electoral votes to Biden's 306.

-ABC News' Benjamin Siegel

White House deputy press secretary Brian Morgenstern told reporters Friday that the president remains willing to take the COVID-19 vaccine when the time is right, while noting that Trump has already been infected with the virus. 

When asked directly if there are concerns about him being vaccinated too close to receiving the monoclonal antibody cocktail, as the Centers for Disease Control and Prevention recommends waiting 90 days between the two, Morgenstern said, "I don't know about concerns." But he added Trump is "perfectly willing to get it, and if the advice is that it is fine -- it will be effective if he takes it sooner rather than later -- he'll do that."

The response comes ahead of Biden being slated to receive the first dose of Pfizer's vaccine on Monday and following Vice President Mike Pence's public vaccination Friday morning.

Morgenstern was also asked to explain why the public has not heard from Trump all week.

"There's a lot of work that goes on that isn't necessarily public, but he is hard at work, and when it's the appropriate time for him to come speak publicly, of course that's his right, his prerogative to do," he said. "But at this point the administration continues to work very hard behind the scenes, and to the extent we have to speak publicly we do that. But the work is being done whether or not he's coming in front of you."

-ABC News' Elizabeth Thomas