McNally has created some of the city’s most successful restaurants, including the French-inspired bistros Balthazar and Pastis. Born in Britain, he was hospitalized in London on Sunday. He posted an Instagram photo of himself with an oxygen tube up his nose.

“Constantly on oxygen and constantly weak,” he wrote, adding that the National Health Service staff “are wonderful.”

McNally told Eater by email that his lungs are improving: “Though still weak and sweating a lot, I feel I’m getting slightly better. Unfortunately, my appetite and sense of humour have gone totally missing.”

Eater noted that McNally, in his 60s, suffered a stroke that left his right side paralyzed and that his children — Sophie and Harry — are helping to run his business. He also partnered with restaurateur Stephen Starr to reopen Pastis last year.

Senior staff at his New York restaurants were not aware that he was in the hospital.

“I’m very concerned, and will find out more,” said a senior team member.

The deadly virus also caused complications that killed top chef Floyd Cardoz last month.