What Pence and Harris say on the stage tonight is important, but only if their messages resonate with American voters.

In a typical election year we'd be travelling to the debates, campaign rallies and talking to voters all across the country.

This year, due to the Covid-19 pandemic, we're doing something a bit different.

Four voters from across the ideological spectrum will join us in a focus group tonight via video chat to give their reactions in real-time as Harris and Pence face-off.

Democrats Shloka and Akayla and Republicans Jim and Gordon will be sharing their perspectives on the two candidates throughout the night. Gordon may be a Republican, but he's still undecided about who to cast his vote for. Will he decide tonight?

You can learn more about our voters here.

And if you're an American voter, you can apply to join our panel here.

President Trump has published a new video message. "Hi, perhaps you recognise me. It's your favourite president," he says as he stands mask-less outdoors in front of the White House Oval Office.

Though he was diagnosed with Covid, Trump claims he did not need to have gone to Walter Reed hospital, where he spent almost three days, but only went because doctors convinced him.

"I went in, I wasn't feeling so hot," he says. In hospital he received treatment that included an experimental drug derived from foetal stem cells.

He vows that the antibody treatment made by Regeneron, a New York-based biotech company, will soon be available to anyone sickened by the virus under an emergency authorisation.

"I want everyone to be given the same treatment as your president. Because I feel great. I feel, like, perfect," he says, calling the drugs he took "a cure".

China will pay for the cost of the medication, he claims, because the pandemic is "China's fault".

Read More: All the medication that Trump is taking, explained

Image source, Getty Images/ New York Times

Up to 6,000 people across the US may have been exposed to Covid-19 by Trump, infected White House aides and senior Republicans, according to an investigation from USA Today.

Those thousands attended rallies, religious services and other gatherings around the country with infected US officials who were at a 26 September White House Rose Garden party suspected of being a "super-spreader" event.

Around 120 of those potentially exposed were in close proximity to Trump himself, USA Today found, external.

Their exposure came in the week after the White House event, before many guests had tested positive for the virus. Over a dozen attendees have since been diagnosed.

Read more:

Trump's White House event in focus over Covid spread

Marianna Spring
Disinformation and social media reporter

Tonight the candidates for US vice-president are preparing to talk about coronavirus, the Supreme Court and gun laws. But millions have been tuning into a parallel conversation happening online filled with conspiracies and rumours.

Conspiracy theories have ramped up after President Trump tested positive for coronavirus, with baseless viral claims suggesting he was faking it – or that the Democrats deliberately infected him. What’s said in this debate could further fuel this disinformation.

Kamala Harris has also been targeted on social media with baseless claims about her heritage and that she’s involved in child-trafficking.

These accusations are frequently promoted by supporters of QAnon – a conspiracy theory that claims President Trump is fighting a secret war against elite Satan-worshipping paedophiles.

Although Facebook has now announced a ban on those supporting the group, there are fears political disinformation spread by QAnon supporters could already have impacted US voters.

During the presidential debate, QAnon helped spread false conspiracy theories about Biden wearing an earpiece to cheat – which were later amplified to millions in ads run by the Trump campaign.

Red, Wine and Blue - a group of suburban women in the battleground state of Ohio - is rallying voters to try and swing the US election in November.

Hear what motivates them:

Image source, Getty Images

Senator Chris Coons, a Democrat from Joe Biden's home state of Delaware, has been speaking to BBC World TV.

Addressing what Biden's foreign policy would look like if he wins the presidency, Coons said: "I am hopeful that we could make reasonably prompt progress towards negotiating a free trade agreement with the United Kingdom... in recognition of this critical special relationship."

Coons, touted as a possible Biden pick for secretary of state, added that the issue of the Irish and Northern Ireland border is "critical" and "has to be handled properly".

"But I do think it is appropriate for us to move towards this sort of close relationship in trade that has long been the case in foreign relations as well," he said, "because we are two countries, so similarly rooted in shared values."

All-American superstar Taylor Swift is all set for tonight's debate, with Biden-Harris cookies in hand and a new magazine article about her political beliefs to boot.

For years, the singer was known for steering clear of politics, which sparked criticism from fans who said she ought to do more with her platform.

But in 2018, she took the plunge by publicly endorsing two Democrats for the mid-term elections.

While the move endeared her to liberals, it made President Trump say he liked her songs "about 25% less now".

Image source, Getty Images

Vice-presidential debates don't usually trouble presidential historians too much, but this year the drama of the election campaign could heighten interest in how the pair fare against each other.

The fact that the president has been seriously ill has reminded the public they have two of the oldest presidential candidates in history. Being first in the line of succession has never been more significant, and both debaters will be aware they have to present themselves as ready to step into the world's biggest job.

The first debate between Trump and Biden was also so bereft of serious policy that some may be aching for a proper discussion about the vision for America being offered by each ticket.

Why this VP debate actually matters

Image source, EPA

Preparations for tonight's debate, at Kingsbury Hall in Salt Lake City, Utah, are nearing completion.

The plexiglass dividers have been installed and the three seats - for both speakers and the moderator - are more than 12ft from each other.

Image source, EPA

The audience - limited in number - will be socially distanced and anyone who removes their face mask will be escorted off the premises.

Image source, Reuters

Ritu Prasad
BBC News writer, Fort Myers, Florida

We’ve been asking our readers for their most pressing questions about the US election. Now it’s our turn to respond.

Click here if you want to know more about this project or send in a question of your own.

Anthony R, 50, from Weston-super-Mare, UK, asks: What will happen if Pence takes over assuming Trump is too ill following a Republican victory? Will Pence remain president until the next election?

There’s no real precedent for this, but fear not: the Constitution is prepared.

The 20th Amendment states that if the president-elect dies after winning but before the inauguration, the vice-president-elect will be sworn in as the new president.

Remember, the nominees don’t officially win until Congress tallies up the votes from the Electoral College, which takes place on 6 January.

Now if the presidential nominee dies after the election but before the electoral votes are counted, we’re in a trickier spot.

The Republican party could select a replacement who the electors would vote for instead (though some state electoral college laws would need speedy changing to allow this).

Joe Biden has been ahead of President Trump in most national polls since the beginning of the year. He has hovered around 50% in recent months and has had a 10-point lead on occasions.

Polls in the battleground states also look good for Biden at the moment. He appears to be ahead in Michigan, Pennsylvania and Wisconsin - three industrial states Trump won by margins of less than 1% to clinch victory in 2016.

By comparison, the polls before the last election were far less clear and just a couple of percentage points separated Trump and his then-rival Hillary Clinton as election day neared.

The BBC's Visual and Data Journalism Team has been keeping track of the latest polls here.

Image source, Getty Images

The only vice-presidential debate of the election campaign gets under way in just a few hours (21:00-22:30ET - 02:00-03:30BST). Let's recap on the main points.

• Vice-President Mike Pence will face his Democratic rival Kamala Harris at Kingsbury Hall, on the University of Utah campus in Salt Lake City
• Extra Covid measures are in place, including plexiglass screens between the speakers plus 12ft of space between both of them and the moderator
• The moderator will be Susan Page, USA Today's Washington bureau chief
• All of those taking part, including the limited audience, must have tested negative for coronavirus ahead of the debate
• Any guest not wearing a face mask will be "escorted out" - a move that follows the presidential debate in which some of Mr Trump's family declined to wear masks
• President Trump's doctor says he has had no Covid-19 symptoms for more than 24 hours and has been fever-free for more than four days
• Our debate coverage will include analysis from our specialist reporters and reaction from our voter panel

Nada Tawfik
BBC News, Salt Lake City

Part of the usual build up to an election debate is the flurry of activity that comes with it.

But because of Covid, there are no campaign surrogates in person here chatting to the numerous members of the press and offering their take on what to expect.

Most media are broadcasting outside on a platform in order to limit the numbers inside the hall. Yet that’s only increased the anticipation for the main event.

Given the circumstances, this might already be one of the most memorable debates ever.

And with two politicians with two very different styles and policies – it has all the potential to be one of the most interesting vice-presidential debates about which direction to take the country.

Unlikely. The presidential debate on 30 September between President Trump and Joe Biden was marred by rancorous exchanges with both men talking over each other. Very little policy was discussed.

Pence vs Harris promises to be a more civilised affair and commentators say could offer a clearer idea of what each presidential candidate has to offer.

It is often said that vice-presidents are only a heartbeat away from the Oval Office and given the age of the two main candidates - Trump is 74 and Biden 77 - voters might well be paying closer attention to tonight's performances.

President Trump’s recent Covid-19 diagnosis has also thrown the fate of two future debates with Biden into doubt - making tonight’s clash all the more important.

Nada Tawfik
BBC News, Salt Lake City

I came across Tom Moran outside the University of Utah’s gates. The former school bus driver told me he had been standing there for several hours each day with his sign, which read “210,000 dead, Covid-19, Trump failed us”. He’d driven 23 hours from Fenton, Michigan to be here to share that message with voters in Utah.

He hopes Kamala Harris speaks truthfully about the coronavirus and criticises President Trump’s recent message to Americans to not let the coronavirus pandemic dominate their lives. The reality for this 65-year-old is that it does dominate his life, and therefore, getting the virus under control is his biggest priority.

The parents of murdered Islamic State (IS) hostage Kayla Mueller will be in the audience at tonight's debate as guests of Vice-President Mike Pence, US media report.

Mueller, an aid worker, was killed by the group in 2015 after being sexually abused by its leader, Abu Bakr al-Baghdadi, according to US officials.

Her parents were critical of the Obama-Biden administration for failing to save her life and later praised President Trump for authorising the mission in which al-Baghdadi was killed. They are still hoping she will be found alive, they recently told BBC News.

News website Axios, externalsays their invitation to the debate suggests a strategy by Pence. With Kamala Harris expected to put him on the spot over the White House's handling of the pandemic, Pence will try to move the conversation on to more favourable ground, it says.

It comes as two IS suspects - known as the Beatles because of their British accents -were charged in the US with terrorism offencesover the killing of four American hostages, including Kayla Mueller.

Tonight's vice-presidential debate is taking place in Salt Lake City, Utah.

Young voters there say they are hoping to see more respect and coherent answers than during last week's presidential debate.

The White House press office has confirmed that President Trump is currently in the White House's Oval Office.

He had been recuperating from his hospital stay in the residential parts of the building, but had been reportedly angling for a return to his work space.

It is not yet known if he plans to stay there long, but a White House spokesman told reporters he is being briefed on stimulus talks and Hurricane Delta, which has made landfall in Mexico.

Critics accused him of pretending to work to stage photo opportunities while in hospital.

The president has been eager to show the nation that he is not fully out of action, and this may be especially true as attention turns to the vice-presidential debate.

We will be bringing you a live stream of the debate, right at the top of this page.

You can also watch on the BBC News and BBC World channels, where a special programme kicks off at 01:30am UK time (20:30 EST).

UK viewers will be able to catch up the morning after via BBC iPlayer, and we will also have video highlights here.

So stay tuned.

Image source, Getty Images

Although Mike Pence tested negative for coronavirus ahead of tonight's debate, one expert is saying more layers of protection are needed, given the current outbreak among President Trump's inner circle.

Dr Neeta Ogden, an internal medicine specialist and immunologist told the BBC's US partner CBS, external that daily test results only reflected a moment in time and couldn't guarantee that an infection wouldn't occur later.

"It's not just Pence, it's the team that he's travelling with, it's the exposure on a daily basis," she said.

Pence's team questioned the need for plexiglass dividers on the stage, something Dr Ogden described as "ridiculous".

She said the plexiglass and the 12ft of distance between each candidate were just "two pieces" of a puzzle.

"We need to make sure there's good ventilation in that auditorium," she said. "Ideally this debate should have been over zoom or should've been outside. I think there's still definitely a risk here."