Biden, 79, is experiencing fatigue, a runny nose and a dry cough after testing positive.

WASHINGTON — President Biden

, raising health concerns for the 79-year-old president and underscoring how the virus remains a persistent threat in a country trying to put the pandemic in the past.

Karine Jean-Pierre, the White House press secretary, said in a statement that Mr. Biden had “tested positive for Covid-19. He is fully vaccinated and twice boosted and experiencing very mild…