Democrat Terry McAuliffe and Republican Glenn Youngkin clashed Tuesday evening over vaccinations, tax policy, education and their respective records in the second and final debate in Virginia’s closely watched gubernatorial election.

The event, hosted by the Northern Virginia Chamber of Commerce at Northern Virginia Community College’s Alexandria campus, quickly got off to a combative start and neither candidate let up over the course of the hour, with each accusing the other of lying to voters.

Five weeks from Election Day and with early voting already underway, recent polls suggest a tight race between former Gov. McAuliffe, who is seeking a second term after his first ended in 2018, and Mr. Youngkin, a former business execu- tive and political newcomer.

Third-party candidate Princess Blanding, who was not invited to participate, interrupted the debate after about 15 minutes, shouting from the audience about the fact that she was shut out. The station broadcasting the debate went to a commercial break.

Ms. Blanding told The Associated Press earlier in the day that the Chamber of Commerce had invited her to sit in the audience and meet with the media afterward.

“The way that felt to me was, ‘Yes, you can come and get on the bus like everybody else ...but you’re going to sit in the back of the bus.’ I met the requirements just like they did to get on the ballot, however, I’m being blocked,” she said.

Democrats made huge gains in Virginia while former President Trump was in office, taking full control of state government. But Republicans are more energized and optimistic about their chances this fall than they have been

in years. The contest, one of only two regularly scheduled governor’s races this year, is also draw- ing national attention as a possible indicator of voter sentiment heading into next year’s midterm elections.

The first question of the night dealt with the coronavirus pandemic, and the candidates maintained the positions they’ve consistently outlined on vaccine mandates, which Mr. McAuliffe generally supports and Mr. Youngkin does not.

“He wants employers to fire employees who don’t get the vaccine,” said Mr. Youngkin, who is vaccinated and said he believes everyone should get it.

Mr. McAuliffe called Mr. Youngkin’s position on the issue “disqualifying.”

Moderator Chuck Todd, NBC News political director, pressed Mr. Youngkin on whether he believed getting vaccinated for “measles, mumps or rubella is a personal choice.”

Mr. Youngkin struggled to find his words for several seconds and then said: “I think that the data associated with those vaccines is something that we should absolutely understand the difference between this vaccine.”

When asked again, he said he thinks those vaccines “can be mandatory.”

Mr. McAuliffe, as he has throughout the campaign, consistently sought to tie Mr. Youngkin to Mr. Trump, who lost Virginia by 10 points. At one point, he called Mr. Youngkin “bought and paid for” by the former president.

“There’s an over/under on how many times you’d say Donald Trump,” Mr. Youngkin responded. “You’re running against me. It’s Terry McAuliffe against Glenn Youngkin.”

In the night’s final question, Mr. Todd asked Mr. Youngkin if he would support Mr. Trump if he ran for president again in 2024. After initially talking around the question, Mr. Youngkin said, “If he’s the Republican nominee, I’ll support him.”

One of the event’s sharpest exchanges came during a question about the state’s historic $2.6 billion surplus, which Democratic Gov. Ralph S. Northam has said is thanks to the state’s strong economic outlook but Mr.

Youngkin has called the result of over-taxation. Asked why some of that money shouldn’t be returned to taxpayers, as Mr. Youngkin has proposed, Mr. McAuliffe argued that the Republican’s “crazy” tax scheme would devastate Virginia’s economy and lead to cuts in public education. “Revenue and expenses, I know were hard for you. I know they’re hard for you,” Mr. Youngkin, a former co-chief executive officer of The Carlyle Group, shot back, to cheers from the audience. “At the end of the day, Terry, you have no idea what you’re talking about.”

While Mr. Youngkin sought to portray Mr. McAuliffe as a failed politician, Mr. McAuliffe went after Mr. Youngkin’s background in private equity, citing unflattering news reports about the performance of some companies his firm acquired, including a nursing home chain that a Washington Post investigation found exposed its patients to “increasing health risks” and racked up health code violations.