The Trump tribe are crisscrossing the United States in an effort to boost their father’s flagging campaign in the final weeks of the election race.

President Trump held his first rally since testing negative to COVID-19 in Florida on Tuesday, telling the crowd he was ‘‘now immune’’.

It comes as American researchers released a report about a Nevada man who seemingly has been infected with the coronavirus twice.

“I feel so powerful I’ll walk into that audience. I’ll walk in there, I’ll kiss everyone in that audience. I’ll kiss the guys and the beautiful women and … I’ll just give you a big fat kiss,” he said.

However, after spending a week on the campaign sidelines, Mr Trump unleashed what he believes to be his most potent weapon – his children.

Tweet from @IvankaTrump

Ivanka and Donald Jr lead the Trump family in an aggressive week of campaigning, in some cases travelling to three states in one day.

But questions are being asked of their coronavirus safety protocols.

“It’s pretty clear whatever changes Trump and his family will make, are minor at most,” said University of Melbourne’s US political analyst Professor George Rennie said.

“It may make him even more reckless, and if Trump is reckless, he’ll want his family to be reckless because he sees them as an extension of himself.”

Ivanka and Don Jr are set to campaign in Georgia this week, a long-held Republican state that is beginning to look vulnerable.

Along with their brother, Eric, the three eldest children have spent weeks travelling across the US in an attempt to court voters.

The Trump children have been aggressively campaigning for the President. Photo: TND

The President’s eldest daughter, Ivanka, is the requested campaign surrogate and is popular with moderates and Mr Trump’s base, Professor Rennie said.

“It’s true to say she’s traditionally had more appeal with moderates and I think that’s still the case, but she’s also very generally well liked by the proper Trump Republican base, which is far from moderate,” he said.

“She’s held up as this American success story.”

The brothers tend to be more obvious in their right-wing talking points, but at the end of the day Ivanka is the clear favourite.

“In terms of Trump’s boys, they are more right-wing in their rhetoric than Ivanka is,” he said.

“But Trump’s view completely dominates the direction of the campaign. Because he sees Ivanka as the poster child, she’s the face of the campaign.”

There are questions about President Trump’s negative test result.

Donald Trump returned to the campaign trail on Monday (US time), but doctors have raised concerns over the negative test result and questioned if the President could still be infectious.

Last week, President Trump tweeted he was “immune” to the novel coronavirus and “can’t give it,” before the White House had declared the negative test results.

The tweet was flagged by Twitter, which said it contained “misleading and potentially harmful misinformation” related to the virus.

In a press briefing, associate professor of immunology and infectious diseases at Harvard Dr Roger Shapiro, said “mild or even moderate disease” may be “rendered non-infectious in about 10 days just by the natural course of the illness and immune control that would be expected for most individuals”.

“However, people with more severe disease can remain infectious for 20 days or even longer,” Dr Shapiro said.

The White House never made clear the severity of Mr Trump’s illness, which can influence how long a person is infectious.

Professor Rennie said it was hard to believe President Trump’s doctors when they had not been transparent about his treatment.

“Everything we’ve heard goes against the advice, you remain contagious for some period, even if you have fought the virus back,” he said.

Tweet from @realDonaldTrump

“We’ve seen Trump has made some minor changes. He’s started wearing masks.

“But Trump and his family have been actively contemptuous about this virus. And contemptuous of the medical advice.”