Former Republican presidential candidate Herman Cain is being treated for COVID-19, a fortnight after he boasted of attending a rally in Oklahoma for Donald Trump without wearing a mask.

It was not immediately clear when or where the 74-year-old, who rose to the top of the polls briefly during the 2012 Republican presidential nomination, was infected.

However, he was taken to an Atlanta, Georgia, hospital less than two weeks after he attended a campaign rally for Mr Trump in Tulsa, Oklahoma. The President’s campaign team said Mr Trump did not meet Mr Cain there.

Tweet from @THEHermanCain

The statement said Mr Cain was taken to hospital after developing “serious” symptoms but was “awake and alert”.

The former pizza company executive has been an outspoken backer of the President and was named by the campaign as a co-chair of Black Voices for Trump.

“I realise people will speculate about the Tulsa rally, but Herman did a lot of travelling the past week, including to Arizona where cases are spiking,” Dan Calabrese, who has been editor of HermanCain.com, wrote on the website.

“I don’t think there’s any way to trace this to the one specific contact that caused him to be infected. We’ll never know.”

The previously reluctant Mr Trump has softened his stance on the issue of wearing masks, although he has been reluctant to be photographed wearing one.

Vice-President Mike Pence has had no such qualms, wearing one to a public briefing on Tuesday where the US surgeon general stressed the importance of Americans doing the same while in public to prevent the spread of COVID-19.

-with agencies