Former President Barack Obama has tested for positive for COVID-19, he announced on Twitter on Sunday.

Former First Lady Michelle Obama has tested negative so far, Obama said.

“I just tested positive for COVID. I’ve had a scratchy throat for a couple days, but am feeling fine otherwise,” the former president tweeted. “Michelle and I are grateful to be vaccinated and boosted, and she has tested negative.”

Obama called his positive test “a reminder to get vaccinated if you haven’t already, even as cases go down.”