US Vice President Mike Pence and his Democratic challenger Kamala Harris squared off in a Wednesday evening debate, separated by plexiglass, only weeks before the November 3 general election. As US President Donald Trump is infected with the coronavirus that has already killed more than 210,000 Americans, the Pence-Harris showdown has taken on an unusually pressing quality. Ms Harris opened the debate with a bruising critique of the Trump-Pence administration's handling of the coronavirus epidemic. "This is the greatest failure of any administration in the history of our country," she said. "They knew and they covered it up. The president called it a hoax." Mr Pence insisted the president had "put the health of America first" and praised the US move to close flights from China. He slammed Ms Harris for questioning whether a vaccine released by the Trump administration could be trusted. "The fact that you continue to undermine public confidence in a vaccine, if the vaccine emerges during the Trump administration, I think is unconscionable," Mr Pence said. The White House has mounted political pressure on the Food and Drug Administration, objecting to stricter guidelines proposed for emergency approval of a coronavirus vaccine. It is unlikely any manufacturer will receive authorisation before the election. While the candidates offered pointed jabs throughout the night, the event was notably tamer and more disciplined than the presidential debate held last week that was marked by interruptions from Mr Trump. Interruptions in the vice presidential debate were largely sparse, but a number of fiery exchanges took place. Ms Harris' sharp and sceptical glances at Mr Pence also caught the attention of social media. A heated exchange on foreign policy began when Ms Harris slammed the Trump administration's policy as being "unilateral" and focused on "isolation". She said the US withdrawal from the Iran nuclear deal meant the US was "in a position where we are less safe because they [Iran] are building up what might end up being a significant nuclear arsenal." Ms Harris also noted that the US president downplayed the brain damage that US soldiers suffered as a result of retaliatory strikes on US troops in Iraq after the killing of Iranian general Qassem Suleimani. "They suffered serious brain injuries and Trump dismissed them as headaches," she said. On the day two alleged members of an ISIS assassination squad, known as "The Beatles", appeared in a US court, the case of Kayla Mueller was highlighted during the debate. The parents of the US humanitarian worker, who was kidnapped by ISIS in 2013 and killed two years later, were present at the debate. Mr Pence said her parents believed Mueller would be alive had Mr Trump handled the case and blasted the Obama and Biden administration for failing to save her. The Obama administration was staunch in its vow not to negotiate with terrorists, but it did make attempts to rescue Mueller. During last week's presidential debate, the president sparked backlash when he failed to condemn the growing number of white supremacist groups in the US. A different tone was struck by Mr Pence, who said both he and the US president denounce white supremacists as he confirmed the Republican party's support for law enforcement, calling the summer protests against racial injustice in the US a "great insult" to police officers. Ms Harris noted her long history as a prosecutor when she responded, "I will not sit here and be lectured by the vice president on what it means to enforce the laws of our country." "I know what I'm talking about, bad cops are bad for good cops. We need reform." One of the most heated exchanges of the night occurred when Mr Pence assailed Democrats for attempting to "pack the court," with more judges. Ms Harris promptly flipped this issue on the vice president, noting that "of the 50 people who President Trump appointed to the court of appeals for lifetime appointments, not one is Black." Following the death of Supreme Court Justice Ruth Bader Ginsburg, the Republican Party has rushed to push Amy Coney Barrett to fill the empty seat, thereby securing that the country's top court would be favourable to Republican policy. Mr Pence attempted to put Judge Barrett's Christian faith at the centre of the Supreme Court debate by condemning attacks from Democrats on her religion, but Ms Harris firmly replied, "it's insulting to suggest we would knock anyone for their faith". She said the Republican Party hoped to use the courts to strike down the Affordable Care Act during a time when the country is in a national health crisis. Ms Harris was resolute that Republicans appointing a new justice to the lifetime appointment during an election year was unacceptable. They walked on stage from opposite side of the debate hall in Salt Lake City, Utah, as the country lurches from one crisis to another. Not only has the president tested positive, coronavirus has spread through his inner circle, infecting dozens of aides, administration staff, senior military officials and Republican politicians. Mr Trump, who is in the White House as he recovers from Covid-19, continued his all-out verbal offensive, calling Mr Biden "a wacko" in a stream of angry tweets posted since he left hospital on Monday. The president is seeing poor polling numbers ahead of the November vote, which comes as the economy stutters from Covid-19 shutdowns that have left countless families and businesses struggling. Mr Trump also keeps warning that he may not accept the election result, arguing that mail-in ballots lead to fraud, while Senate Republicans are rushing to confirm the president's Supreme Court nominee even as some in their caucus are in quarantine. The unique political storm is enough for Brookings Institution senior fellow John Hudak to call Utah's face-off "the most important vice presidential debate in American history". Mr Pence is under pressure to signal some stability and relay an administration plan for how to tackle the pandemic four weeks from election day. "Vice President Mike Pence is ready. He is prepared to prosecute the case against the California radical extremist of Kamala Harris," Trump campaign adviser Mercedes Schlapp told Fox News, setting the tone for the debate. "We know that Mike Pence will be able to also talk about the president's strong accomplishments on the economy and also on combating Covid." There is little appetite, though, for a repeat of the Trump-Biden debate, which was marred by their constant interruptions and personal insults. Wednesday's event has strengthened health measures, with organisers agreeing to allow Ms Harris to be separated from Mr Pence by plexiglass. Some of Mr Pence’s supporters had originally laughed at the measures, which were suggested by Ms Harris’s team. Both participants have tested negative for coronavirus. "If the Trump administration's war on masks has now become a war on safety shields, that tells you everything you need to know about why their Covid response is a failure," Ms Harris's press secretary Sabrina Singh said. "Masks save lives," Ms Harris said on Twitter on Wednesday. Still being treated for the coronavirus after three nights in hospital, Mr Trump has scrambled to resume his re-election campaign. The latest polls forecast victory for Mr Biden, with CNN giving the Democrat a national advantage of 57 percent to 41 percent among likely voters. White House doctors say he is recovering rapidly and Mr Trump is doubling down on his controversial position that Covid-19 is taken too seriously, painting himself as a fighter who took on the virus and won. After urging Americans to stop fearing Covid-19 and "don't let it dominate you," he attacked the media for not paying more attention to what he said were his many successes. Mr Trump and Mr Biden are scheduled to square off again on October 15, but the former vice president believes "if he [Trump] still has Covid, we shouldn't have a debate".