A live TV debate between the candidates for vice-president ahead of next month's US election has seen fierce clashes over the coronavirus pandemic.

Democrat Kamala Harris accused Donald Trump of "the greatest failure of any presidential administration" in history.

Vice-President Mike Pence, a Republican, said her party's pandemic plan amounted to "plagiarism".

Mr Pence did not interrupt as much as the president last week, but when he did Ms Harris interjected: "Mr Vice-President, I'm speaking, I'm speaking."

Indeed the viral moment on Wednesday night that seemed to create the most buzz was a fly landing on Mr Pence's head and remaining there for some two minutes.

I watched the debate this morning - perhaps those two should be running for President rather than the other two no hopers.

Earlier the commission deciding the 15 October Miami debate's format said it would have to take place remotely.

It made the decision after Mr Trump was treated for Covid-19. He has no current symptoms but the White House is tackling a cluster of positive tests.

Mr Trump said the move to virtual was to "protect" his rival.

Mr Biden's campaign said he would participate. The Democrat's campaign said he "looks forward to speaking directly to the American people".

Trump said: "I'm not gonna waste my time on a personal debate. Sit behind a computer, ridiculous. They cut you off... I'm not doing a virtual debate."

He will hold a rally at the same time instead.

The Commission on Presidential Debates (CPD) announced on Thursday that the debate scheduled for 15 October would be conducted virtually for "the health and safety of all involved".

However, the CPD said in a statement on Friday: "Subsequently, the campaigns of the two candidates who qualified for participation in the debate made a series of statements concerning their respective positions regarding their willingness to participate in a virtual debate on 15 October, and each now has announced alternate plans for that date.

"It is now apparent there will be no debate on 15 October, and the CPD will turn its attention to preparations for the final presidential debate scheduled for 22 October."

The final debate will take place at Belmont University in Nashville, Tennessee, "subject to health security considerations"*.

The microphones of President Trump and Joseph R. Biden Jr. will be muted during portions of the final presidential debate on Thursday, the organizers said late Monday, in an unusual effort to avoid the unruly spectacle of the candidates’ first meeting in Cleveland last month.

The debate’s rules remain the same: Each candidate will be allotted two minutes to initially answer the moderator’s questions. But the Commission on Presidential Debates said it would turn off each candidate’s audio feed while his rival had the floor.

Once each candidate has delivered his two-minute reply, Mr. Trump and Mr. Biden, the Democratic nominee, will be allowed to freely engage with each other for the remainder of each 15-minute segment, with both microphones fully functional.

The incoherence of the first debate — during which Mr. Trump’s relentless interruptions of Mr. Biden and the moderator, Chris Wallace of Fox News, derailed the proceedings — put pressure on the nonpartisan debate commission to improve enforcement of the rules, despite its members’ longstanding reluctance to change any aspects of the debates in the middle of a campaign.

The moderator of Thursday’s debate in Nashville, Kristen Welker of NBC News, will not be in control of turning the candidates’ microphones on and off; that task will be left to the commission’s production crew. There is also the potential for a new kind of gaffe: Mr. Trump’s voice may be picked up by Mr. Biden’s microphone, and vice versa, meaning that an attempted interruption may still be heard, at least faintly, by viewers watching at home.

The 90-minute debate will have no commercial breaks. It will be divided into six 15-minute segments, with each candidate given two uninterrupted minutes before they enter into open debate. Here comes the important difference from the first debate, which was filled with interruptions: during these two-minute blocks, only the candidate who has the floor will have his microphone turned on - the other will be temporarily muted.

The six segments will address six separate topics:

• Fighting Covid-19
• American Families
• Race in America
• Climate Change
• National Security
• Leadership

And in terms of coronavirus, safety protocols are expected to be similar to the first Trump-Biden face-off. Candidates will be spaced a safe distance apart and they will not shake hands.

Trump's way - or the law of the jungle.