Washington DC: Donald Trump claimed on Sunday (October 11) that he was now “immune” to coronavirus after leaving hospital just six days earlier, ahead of plans for a string of campaign rallies in swing states from Monday.

“It does give you immunity,” Trump told Fox News on Sunday, a claim not supported by scientists, adding that he no longer had the disease.

In a memo released Saturday night by the White House, Navy CMDR Dr Sean Conley said Trump met the Centers for Disease Control and Prevention criteria for safely discontinuing isolation and that by "currently recognized standards" he was no longer considered a transmission risk. The memo did not declare Trump had tested negative for the virus.

But sensitive lab tests - like the PCR test cited in the doctor's statements - detect virus in swab samples taken from the nose and throat. Some medical experts had been skeptical that Trump could be declared free of the risk of transmitting the virus so early in the course of his illness.

Trump took off a mask moments after he emerged on the balcony to address the crowd on the lawn below, his first step back onto the public stage with just more than three weeks to go until Election Day.

He flouted, once more, the safety recommendations of his own government days after acknowledging that he was on the brink of "bad things" from the virus and claiming that his bout with the illness brought him a better understanding of it.

The President has been attempting to defend his pandemic record in the US, which has recorded the highest number of cases and deaths in the world and convince Americans he is Covid-free. He returns to the campaign trail seeking to narrow a large polling gap with Democratic challenger Joe Biden with only 23 days until the election. A Washington Post-ABC News poll on Sunday had Biden favoured by 54% of likely voters, ahead of Trump with 42%.