Moderator Susan Page posed the first question to Harris, revealing the first of nine topics: The coronavirus pandemic.

Noting the president's recent diagnosis, Page asked Harris, "What would a Biden administration do in January and February that a Trump administration wouldn't do?"

True to her form as a prosecutor, Harris -- the first Black woman and first Indian American to take a vice presidential debate stage -- laid out her facts, arguing the administration knew about the threat of the virus in January but didn't act soon enough.

"They were informed that it's lethal in consequence, that it's airborne, that it will affect young people," Harris said. "They knew what was happening and they didn't tell you."

Harris then said the Trump administration still doesn't have a plan.

"Well, Joe Biden does and our plan is about what we need to do around a national strategy for contact tracing, for testing, for administration of the vaccine, and making sure that it will be free for all," she said.

There was no handshake between candidates -- customary at the top of such events -- due to COVID-19 precautions. The audience, limited to under 100 attendees, applauded Pence and Harris as they took the stage.

Former Democratic 2020 presidential candidate Pete Buttigieg, who played Pence at some mock debate rehearsals for Harris, was also spotted in the audience.

Pence and Harris have taken the stage in Salt Lake City for the vice presidential debate. The candidates skipped the traditional handshake due to COVID-19 and are divided by plexiglass.

Harris' chief of staff Karine Jean-Pierre told ABC News Chief Anchor George Stephanopoulos that Harris won't spend the night fact-checking Pence on stage.

Instead, the former prosecutor will "bring the case forward" on how Biden and Harris could lead to a different America.

"This debate is about Donald Trump's failure to contain COVID-19, and not just that but to also help working families," said Jean-Pierre, adding Harris has a "very diverse team" that has prepared her for the debate.

Jean-Pierre also criticized the example Trump has set since testing positive for the novel coronavirus last week.

"You have a president right now when he left the White House, he decided that he was going to make a campaign by removing his mask. His rhetoric has been incredibly dangerous," she said. "As Joe Biden said, it's a tragedy that he believes that he was blessed to have this virus, when people are suffering."

Marc Short, Pence's chief of staff, noted that Harris, like Pence, is "also a very skilled debater and has a record as a prosecutor, so I think it will be a very engaging conversation for the American people and hopefully one that shows a clear contrast in visions between the two campaigns."

Short said Pence will argue the case that the Trump administration protected more American lives in its COVID-19 response.

With less than a month to go until the election, early voting has already begun in 33 states and at least 5.5 million votes have been cast -- hitting record numbers across the nation.

According to the United States Elections Project, spearheaded by the University of Florida's political expert, Michael McDonald, an unprecedented 5,618,155 voters have already voted and at least 69,786,179 ballots have been requested in early voting states.

The coronavirus pandemic plays a factor in explaining the large early voting numbers as well as an increase in voter interest. Voters in 2020 are more eager to cast a ballot ahead of Election Day where polling sites could be viewed as overcrowded during pandemic standards.

Seven states --- California, Colorado, Hawaii, Nevada, Oregon, Utah and Washington -- have an all-mail ballot election meaning anyone registered to vote automatically receives a ballot to their registered address.

-ABC News' Kelsey Walsh

One thing that remains absent from Pence's speeches at campaign events is how he envisions providing health care for Americans. The Trump/Pence campaign in 2016 ran on a "repeal and replace" position of Obamacare and have repeatedly gone through the court system to try to dismantle the Affordable Care Act during their first-term. They have yet to put out a replacement plan since taking office.

Like Trump, Pence has also expressed the need to protect Americans with preexisting conditions, even though the Trump Administration is currently asking the U.S. Supreme Court to strike down Obamacare in its entirety, which already protects those vulnerable Americans.

As recently as September, during a town hall moderated by ABC News Chief Anchor George Stephanopoulos, Trump was pressed about his repeated claims to deliver a health care plan without following through. Trump said, "I have it already, and it's a much better plan," but he has not delivered.

On Sept. 24, Trump did sign several executive orders, framing them as his "America First Health Care Plan," which are not legislative proposals, but rather administrative actions. He claimed his new plans cost 60% less than options under Obamacare, an end to surprise billing and protections for Americans with preexisting conditions, which is already covered under the ACA.

Harris was initially a supporter of "Medicare for All" and backer of Sanders' plan which would get rid of private health insurance. During the presidential primary, Harris changed her position, instead calling for an expansion of health care access while still allowing for private health insurance. Harris, in an interview with Axios in October 2019, acknowledged that she'd been "called a flip-flopper for that."

As the Democratic vice presidential nominee, Harris has backed Biden's health plan which would provide a public option for Americans seeking health care and aim to lower costs.

-ABC News' Justin Gomez and Averi Harper