Biden warns of 'dark winter' ahead as he lays out COVID-19 plan, calls for unity on masks

President-elect Joe Biden in his first solo remarks to Americans since his victory speech over the weekend reminded Americans of the ongoing coronavirus pandemic as cases and hospitalizations rise across the country, and said the country is “still facing a very dark winter” before offering his plan to combat it. 

"We are ready to get to work addressing the needs of the American people. Today, that work begins," Biden said from The Queen Theater in Wilmington Delaware, following a briefing with his newly-announced COVID-19 advisory board. "It starts with doing everything possible to get the COVID-19 under control, so that we can reopen our businesses safely and sustainably, resume our lives, put this pandemic behind us."

While he praised the announcement from Pfizer Monday morning that the company has a vaccine in trial that looks "90% effective in preventing COVID-19," Biden reminded that even if the vaccine is approved, it will not be widely available for months. He went on to urge all Americans, regardless of whether they voted for him, to "end the politicization of basic responsible public health steps."

"This election is over. It’s time to put aside the partisanship and the rhetoric that’s designed to demonize one another," Biden said, reminding Americans to keep social distancing and wearing a mask.

"Doesn't matter who you voted for, whether you stood, where you stood before election day, doesn't matter your party, your point of view. We can save tens of thousands of lives if everyone would just wear a mask for the next few months. Not Democrat or Republican lives, American lives," he added. "A mask is not a political statement but it is a good way to start pulling the country together."

After pledging to rejoin the World Health Organization on "Day One," Biden also said his advisory board will include experts on global health security, "so that we can restore U.S. global leadership to fight this pandemic" -- in sharp contrast to Trump's isolationist approach to the virus and general policy.

President-elect Joe Biden and Vice President-elect Kamala Harris met with their newly-announced COVID-19 advisory board via Zoom Monday morning at the Queen Theater in Wilmington, Delaware, for a briefing on the coronavirus pandemic -- a signal of Biden’s primary focus as he prepares to take office in 72 days.

"Dealing with the coronavirus pandemic is one of the most important battles our administration will face, and I will be informed by science and by experts," Biden said in the release announcing the board which he says will guide his approach to managing spikes, distributing safe vaccines and protecting at-risk populations.  

As previously reported, the team will be led by 3 co-chairs: former Surgeon General, Vivek Murthy, and former Food and Drug Administration commissioner, Dr. David Kessler, along with Dr. Marcella Nunez-Smith, a professor of medicine at Yale University.

In total, 13 co-chairs and members comprise the board, including former director of the Biomedical Advanced Research and Development Authority (BARDA), Dr. Rick Bright, who made headlines earlier this year when he resigned from his role at the National Institute of Health and filed a whistleblower complaint over "an abuse of authority or gross mismanagement" at the Department of Health and Human Services on the COVID-19 response.

Aside from their victory speeches Saturday night, this is the first public event for the Biden and Harris since being projected as the winners of the 2020 election.

-ABC News’ Molly Nagle

Even if you knew in advance about the "blue shift" that would occur in states like Pennsylvania -- and FiveThirtyEight did know in advance about it! -- it’s been hard to make enough of a mental adjustment for it this week.

Numbers flashing across a TV ticker have a certain magnetic power and certitude to them. It was easy to forget that Joe Biden would gain ground once mail votes were added to the tallies because such votes were overwhelmingly Democratic this year in Pennsylvania and most other states.

But just because of that blue shift -- and the red shift that occurred in states where mail votes were counted first -- that doesn’t mean the presidential race was all that close in the end. Joe Biden’s win was on the tighter side of the likely range of outcomes suggested by the polls, but it was a thoroughly convincing one judged on its own merits.

-FiveThirtyEight editor in chief Nate Silver

Read the full analysis here.

Two Donald Trump associates held a news conference in Las Vegas alleging voter fraud in the state, but they provided little proof and didn't announce any legal actions.

Former Nevada Attorney General Adam Laxalt and American Conservative Union chairman Matt Schlapp spoke outside the Clark County Election Department, providing a number of anecdotal stories of voter fraud.

Among the unverified allegations were repeated complaints about the machine used to verify voter signatures and charges that Republicans were denied the right to vote.

The pair also claimed that hundreds of dead people voted in Clark County.

Laxalt and Schlapp said they had no legal action to announce at the briefing.

Two days ago, a Clark County judge denied a request by the GOP to halt the use of the signature verification machines, saying the devices were lawful and that observers were watching the count. The judge also criticized GOP representatives for not providing any evidence of wrongdoing.

-ABC News' Michelle Mendez, Matthew Fuhrman and Cheyenne Haslett