LONDON—British Prime Minister Boris Johnson, battling a really serious coronavirus an infection, was admitted to the intensive care device of a London healthcare facility Monday evening, leaving his country’s management in question at a second of deep disaster as the virus’s spread accelerates.

As Mr. Johnson’s situation worsened, he deputized his foreign secretary, Dominic Raab, to run the authorities, a spokesman explained. The fifty five-year-aged leading was conscious when he was wheeled into the intensive care device of a central London healthcare facility at all around 7 p.m….