The first Western leader to get an acute case of COVID-19 has now been hospitalized ten days after first showing symptoms. The British government announced that Boris Johnson’s admission to hospital was more of a precautionary measure, but his persistent high fever points to a serious problem.

The BBC reports that Johnson remains in command of the executive — for now:

Prime Minister Boris Johnson is “still very much in charge of the government” despite spending the night in hospital with coronavirus, Housing Secretary Robert Jenrick has said.

The PM was taken to a London hospital on Sunday evening with “persistent symptoms” – including a temperature – for a series of routine tests.

It is said to be a “precautionary step” taken on the advice of his doctor. …

Mr Jenrick told BBC Breakfast: “We hope that as a result of these tests [the prime minister] will be able to come back to Downing Street as soon as possible.

“He’s been working extremely hard leading the government and being constantly updated. That’s going to continue.”

The announcement came just after the broadcast of a pre-recorded message from Queen Elizabeth II intended to rally the nation in the crisis. It is only the fourth time the monarch has addressed the UK during her 68-year reign, which shows just how much the government didn’t need Johnson’s setback at the moment:

The Queen represents continuity, but Johnson’s hospitalization threatens to disrupt it, at least in terms of public calm. Johnson is a charismatic and irreplaceable political figure, and his vision for Brexit managed to muscle the UK through political gridlock that had lasted nearly three years. If Johnson gets sidelined — or worse — Raab will have a tough time replicating Johnson’s successes.

Donald Trump took a moment at last night’s coronavirus press briefing to send his best wishes to his “friend” and “great leader”:

President Trump joined a chorus of voices wishing the prime minister a quick recovery from the illness.

“But before I begin, I want to express our nation’s well wishes to Prime Minister Boris Johnson as he wages his own personal fight with the virus,” he said last night. “All Americans are praying for him. He’s a friend of mine. He’s a great gentleman and a great leader, and he’s as you know, he was brought to the hospital today, but I’m — I’m hopeful and sure that he’s going to be fine.”

We’re praying for all our friends in the UK at the moment anyway for health and security, it goes without saying. If one can be permitted to look past the acute crisis, however, it’s easy to view Johnson as a special case for prayers and hopes. Trump and Johnson had planned to work out a trade deal and to pull the US and UK into a tighter relationship than ever after the UK’s split from the EU. Trump had talked about that with Theresa May too, but May kept a greater distance from Trump than Johnson has. How much of the promise of those closer ties will recede if Johnson isn’t in charge to fulfill it? Boris is indispensable to the Tories, but perhaps also to the White House.

Update: Johnson sent out a message on Twitter emphasizing the “routine” nature of his hospital stay, under the circumstances. He also hailed the work of the National Health Service:

That’s the kind of stiff upper lip that will give Britons some comfort in the crisis, especially seeing as how Johnson’s still using Twitter. Or his staff is, anyway.