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."

California Attorney General Xavier Becerra, Biden's nominee to lead the Health and Human Services Department who would be the first Latino in the position if confirmed, said the incoming Biden administration will elevate the knowledge of medial professionals and build a country where health care is a right, not a privilege.

"At HHS, tackling pandemics, saving lives, keeping us healthy, should be our calling card. And we won't forget that there is a second "H" in HHS, the human services: the work we do for our children, the seniors and and disabled. They will stand tall in a Biden-Harris HHS," Becerra said.

Becerra also shared a personal story, of his father passing away peacefully at home on New Year's Day, contrasting it to the present moment.

"No one should ever have to die alone in a hospital bed, loved ones forced to stay away. That seems so contrary to the values of a great nation, the values that drew my parents like generations before and after them to come to America," he said.

Becerra led the states' defense of the Affordable Care Act after the Trump administration sued to dismantle the program earlier this year.

Ahead of introducing his health care picks, Biden made his mask campaign official and called on all Americans to wear a mask for the first 100 days of his presidency as part of three key objectives he's asking his health care team to complete in his first 100 days in office.

"My first 100 days won’t end the COVID-19 virus. I can't promise that," Biden said. "We didn’t get into this mess quickly. We're not going to get out of it quickly. It's going to take some time. But I'm absolutely convinced that in 100 days we can change the course of the disease and change life in America for the better."

Biden said his team's second initiative is to have "at least 100 million COVID vaccine shots into the arms of the American people in the first 100 days." The initiative comes as the Biden team has said it's seen "no detailed plan" on vaccine distribution from the Trump administration.

Finally, Biden said getting children back to school and keeping them in school will be a "national priority" for the team in the first 100 days, saying Congress can help make this happen with the appropriate funding.

"I'm encouraged by the bipartisan efforts in Congress around a $900 billion economic relief package which I've said is critical, but this package is only a start for more action early next year," Biden added.

Biden is introducing a slate of health care experts and officials who will lead his administration's response to the ongoing COVID-19 crisis.

"Today, I’m very proud to be announcing our health care and COVID team at a critical time, as we near the end of one of the toughest years we've faced as a nation," Biden said, adding this group of "world class experts" will be "ready on day one."

California attorney general and former California congressman, Xavier Becerra, is Biden's nominee for secretary of Health and Human Services. If confirmed, he would be the first Latino to lead the department.

Vivek Muthy has been nominated to be U.S. surgeon general, a role he served in during the Obama administration.

Dr. Rochelle Walensky, a leading expert on virus testing, prevention and treatment, is nominated to serve as director of the Centers for Disease Control and Prevention.

Dr. Marcella Nunez-Smith, one of the country’s foremost experts on health care disparities, will serve as the COVID-19 equity task force chair.

As Biden said last week, Dr. Anthony Fauci will stay on in his current role as as director of the National Institute of Allergy and Infectious Diseases and will take on the elevated role of Biden's chief medical adviser on the COVID-19 pandemic.

Jeff Zients will serve as coordinator of the COVID-19 response and counselor to the president, and Natalie Quillian will serve as deputy coordinator of the COVID-19 response.

Sparks flew Saturday as justices on the Wisconsin Supreme Court questioned Jim Troupis, a lawyer for the Trump campaign who argued that the state should throw out 220,000 votes from Dane and Milwaukee counties.

Justice Jill Karofsky lit into Troupis under 10 minutes into the hearing, accusing the campaign of trying to disenfranchise Black voters.

“In your lawsuit, what you have done here, is you have targeted the vote of almost a quarter of a million people, a quarter of a million people not statewide in Wisconsin, but … in two of our 72 counties, two counties that are targeted because of their diverse populations, because they're urban; I presume because they vote Democratic. This lawsuit, Mr. Troupis, smacks of racism,” Karofsky said.

Troupis and the Trump campaign argued that the court should throw out four categories of votes they said did not follow state statute, including absentee ballots delivered in person at a “Get Out the Vote” event in a park, ballots applied for with a specific mail-in form, ballots missing the address of a signed witness and ballots applied for by “indefinitely confined voters.”

As the hearing continued, Justice Rebecca Dallet once again homed in on the demographic makeup of Milwaukee and Dane counties, noting that the Trump campaign was “not asking … to throw out votes in any other county.” Troupis became defensive, telling the justices that the Biden campaign could have asked for the recount to encompass the whole state.

“You made a statement, as if this was a choice based on criteria that simply are not true,” Troupis said before Dallet jumped on him.

“Who chooses which counties to ask for a recount?” Dallet asked.

Troupis responded “the candidate,” to which Dallet noted the president “had a choice when it came to the recount of which counties. … He chose to only challenge votes in the most urban, non-white, largest counties that voted overwhelmingly for Joe Biden.”

-ABC News' Alex Hosenball and Matt Mosk