WASHINGTON (AFP) - Former US president Barack Obama has tested positive for Covid-19, with mild symptoms.

“I’ve had a scratchy throat for a couple days, but am feeling fine otherwise,” Mr Obama said on his Twitter account on Sunday (March 13), adding that his wife, former first lady Michelle Obama, has so far tested negative.

“Michelle and I are grateful to be vaccinated and boosted,” he wrote.

Mr Obama, plus fellow former presidents Jimmy Carter, George W. Bush, Bill Clinton – and the former first ladies – appeared together in a one-minute video released last March endorsing the US vaccination campaign and sharing what they missed about pre-pandemic life.

“This vaccine means hope,” Mr Obama said in the video. “It will protect you and those you love from this dangerous and deadly disease.”

In August, Mr Obama scaled back his 60th birthday celebrations because of the spread of the Delta variant of the coronavirus.

Conservative political opponents had lashed out at the former president for planning to host an outdoor party – in which attendees were required to be vaccinated – that had been expected to draw hundreds of guests after Democrats had criticised Mr Donald Trump’s administration for organising several mask-less events at the White House.

Mr Obama reiterated his support for the vaccine in his tweet on Sunday, saying his own positive test was “a reminder to get vaccinated if you haven’t already, even as cases go down”.

Despite a vocal anti-vaccination constituency in the country, the US Centres for Disease Control and Prevention (CDC) says more than 80 per cent of all people aged five and older in the United States have had at least one Covid-19 vaccine dose.

US daily case counts have fallen off sharply, according to the CDC, with an average of around 35,000 cases per day in mid-March compared with a peak of an average of 810,000 cases per day in mid-January.