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

PENCE'S CLAIM: "When President Trump and I took office, America had gone through the slowest economic recovery since the great depression. ... We're going through a pandemic that lost 22 million jobs at the height, we've already added back 11.6 million jobs."

FACT CHECK: With September's jobs report, over 11.4 million jobs have been added since March. But job gains have slowed in the past three months, showing the recovery is starting to lose momentum.

In September, 661,000 jobs were added, which was worse than expectations. The unemployment rate also declined to 7.9%, better than expectations.

The jobs number represented a significant slowdown in the number of jobs added since the economy started opening up after the pandemic induced shutdown.

Airlines such as United and American notified over 30,000 employees that they would be laid off or furloughed because the federal aid expired. Disney, the parent company of ABC News, announced it was eliminating 28,000 theme park jobs in Florida and California, and Cineworld, parent company of Regal Cinemas, the second-largest theater chain in the United States, said Monday that it will close all of its U.S. and U.K. theaters indefinitely, affecting 45,000 employees. These positions weren't included in the September report.

In September, the number of permanent job losses increased by 345,000 to 3.8 million; this measure has risen by 2.5 million since February.

Though the expansion of the U.S. economy was slow under the start of the Obama administration during the Great Recession, in the final four years GDP growth was at a 2.3%, nearly similar to the 2.5% in the first three years of Trump, according to The Associated Press.

--ABC News' Justin Gomez, Layne Winn and Zunaira Zaki