Republicans and Democrats on the congressional committee planning next month's inauguration squabbled Tuesday morning over the election results, with Republicans voting against a measure from House Majority Leader Steny Hoyer acknowledging Biden's victory.

"I made a motion that the committee notify the American people that it is preparing for the inauguration of Joseph Biden and Kamala Harris, and in consultation with them and health experts are doing so to protect the health of our people," Hoyer told reporters after the meeting. "That motion was defeated three to three."

All three Republicans on the panel -- Senate Majority Leader Mitch McConnell, Senate Rules Committee Chairman Roy Blunt and House Minority Leader Kevin McCarthy -- voted against the measure, while Democrats on the panel -- Hoyer, House Speaker Nancy Pelosi and Sen. Amy Klobuchar, D-Minn. -- voted in favor.

Even as they refuse to acknowledge Biden's victory, Republicans called Hoyer's move a stunt that has no bearing on planning the inauguration: They are already working with Biden's inaugural committee, and the measure wasn't relevant to the day's meeting.

“It is not the job of the Joint Congressional Committee on Inaugural Ceremonies to get ahead of the electoral process and decide who we are inaugurating. The JCCIC is facing the challenge of planning safe Inaugural Ceremonies during a global pandemic," Blunt said in a statement. "I would hope that, going forward, the members of the JCCIC would adhere to the committee’s long-standing tradition of bipartisan cooperation and focus on the task at hand.”

-ABC News' Benjamin Siegel

Dr. Rochelle Walensky, chief on infectious diseases as Massachusetts General who was tapped as Biden's pick to lead the Centers for Disease Control and Prevention, said her work on the HIV/AIDS pandemic brought her to this moment and said she is “honored” to serve an administration that will let science lead.

"I've dedicated my career ever since to researching and treating infectious diseases, and to ending the HIV/AIDS crisis for good. Now a new virus is ravaging us. It's striking hardest once again at the most vulnerable: the marginalized, the underserved," she said. "The pain is accelerating. Our defenses have worn down. We are losing life and hope at an alarming rate."

Walensky said she never anticipated taking on the role in government but compared the nation to a dying patient, said it's her calling as a doctor to respond.

"Every doctor knows that when a patient is coding, your plans don't matter. You answer the code. And when the nation is coding, if you are called to serve, serve. You run to take care of people, to stop the bleeding, to stabilize, to give them hope and a fighting chance to come back stronger," she said.

Director of the National Institute of Allergy and Infectious Diseases Dr. Anthony Fauci, who will stay on Biden's COVID-19 equity task force and take on the elevated role of chief medical adviser, appeared virtually at Biden's rollout and expressed support for Biden's initiatives around masks and vaccinations in his first 100 days in office.

"I believe, as you do, that in the fight against this pandemic, we must lead with science and that a key piece of our ongoing work is communicating consistently with the American people," Fauci began.

"Whether it's maintaining social distancing and not congregating indoors, or the 100-day challenge you described on masking or to get as many people vaccinated as possible, these actions are bold, but they are doable and essential to help the public avoid unnecessary risks, to help us save lives, reopen schools and businesses and to eventually beat the pandemic," he continued.

Acknowledging he's dealt with many public health crises in his career, Fauci said the COVID-19 pandemic is "the toughest one we have ever faced as a nation," and repeated Biden's warnings that a dark winter is ahead.

"The road ahead will not be easy. We have got a lot of hard and demanding work to do in the next year, but as we have done during previous crises, I also know we can get through this pandemic together as a nation," Fauci added, thanking Biden for the opportunity to serve in this capacity.

Fauci explained he wasn't able to attend the event in-person because his colleague at the NIAID is receiving the Nobel Prize in medicine Tuesday.

Biden's nominee for surgeon general, Dr. Vivek Murthy, who served in the same role in Obama administration, reminded in his remarks that COVID-19 is not the only health crisis devastating families and shortening life spans in America while warning that even with the best policies, the nation must overcome the fear and distrust that many are feeling amid the pandemic.

"In my new expanded role, I will work to bring a health focus to our policies across government so that our schools, our workplaces and our communities can be forces for strengthening our health and wellbeing, but the truth is that the very best policies, and even the best vaccines and treatments, will not heal our nation unless we also overcome the fear, anxiety, anger and distrust that so many Americans are feeling right now," Murthy said.

"So more than anything, I will come to this role as a doctor, one who learned the most important lessons about medicine not in medical school, but from the clinic that my parents opened when they first came to America as immigrants decades ago," he added.

Drawing from personal experience, Murthy went on to say he is "endlessly grateful to serve one of the few countries in the world where the grandson of a poor farmer in India could be asked by the president-elect to look out for the health of an entire nation."

Trump and Biden hold dueling events on the pandemic response Tuesday with the president hosting a "vaccine summit" at the White House, just days before a Food and Drug Administration advisory committee holds a hearing on whether to authorize emergency use of a COVID-19 vaccine, while the president-elect is slated to formally roll out his health care picks who will take over handling the COVID-19 pandemic in 43 days.

At his event, Trump is slated to sign an executive order touting his mantra of "America First" that would prioritize Americans’ access to COVID-19 vaccines before the United States helps other countries. But the chief science adviser to "Operation Warp Speed," the U.S. government's initiative to expedite vaccine development which Trump is also expected to tout, said Tuesday morning he doesn't know about the vaccine-related executive order Trump is expected to sign.

"Frankly, I don't know and, frankly, I'm staying out of this. I can't comment," Dr. Moncef Slaoui told ABC News Chief Anchor George Stephanopoulos in an interview Tuesday on "Good Morning America,” when asked to explain the executive order.

The event comes as a senior administration official familiar with the matter confirmed reporting to ABC News that the Trump Administration passed when Pfizer offered in later summer to sell the U.S. more COVID-19 vaccine doses -- an approach which the White House has denied and Slaoui defended Tuesday. Representatives of Pfizer and Moderna -- the two drug companies seeking emergency-use authorization -- are not expected to attend the White House summit, nor is anyone from the Biden transition team.

Biden, meanwhile, is slated to introduce the health care team he will entrust with handling the pandemic California Attorney General Xavier Becerra as Health and Human Services secretary, the first Latino to hold the post if confirmed. Director of the National Institute of Allergy and Infectious Diseases Dr. Anthony Fauci, who is taking on the elevated role of chief medical adviser to Biden in the incoming administration, is expected to dial into Biden’s meeting, though not the one at the White House.

Biden and Vice President-elect Kamala Harris are also meeting Tuesday with several civil rights leaders including NAACP representatives to discuss policy issues around racial equity as well as diversity and representation on the incoming Cabinet. It comes after news leaked that Biden is expected to name retired four-star Army Gen. Lloyd Austin as his defense secretary, who would be the first African American in the post if confirmed, this week.

Tuesday is also the congressionally mandated "safe harbor" deadline -- the date, under federal law, by which the "final determination of any controversy or contest concerning the appointment" of electors "shall be conclusive” -- making it extremely difficult to dispute election results in the courts, where pro-Trump efforts have seen at least 39 defeats to date.