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LONDON — No one is sugarcoating the coronavirus in the United Kingdom.

Experts in the government have revealed that as many as 10,000 might already be infected in the country, with Prime Minister Boris Johnson warning Thursday, "I must level with you, the British public: Many more families are going to lose their loved ones before their time."

And yet the U.K. is becoming increasingly isolated in its response to the pandemic. It is one of the only major countries of Western Europe to impose few, if any, restrictions on daily life.

The U.K.'s tactics, which are backed by its top team of epidemiologists and behavioral psychologists, have left many here asking: Why do our experts disagree with those in most other countries?

The disparity has also highlighted that while "flatten the curve" has become something of a mantra, there is considerable disagreement among experts about the best way to achieve that.

The U.K. has emerged somewhat out on its own in the international community.

Thursday brought a major shift in its government strategy, moving from the "contain" to the "delay" phase of its plan. That effectively concedes that the virus is here, that it will spread rapidly and widely through society, and the focus should be on slowing it down.

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The U.K's Electoral Commission said Friday it was postponing more than 300 local elections for 12 months, including the contest to be London mayor which was due to be held on May 7.

But still, the government did not introduce measures to close schools, ban large gatherings or sporting events, or impose restrictions on travel, like some had predicted it might.

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"The most important thing individuals can do to protect themselves remains washing their hands more often," updated guidelines read. "Make sure you cough or sneeze into a tissue, put it in a bin and wash your hands."

Anyone with a fever or a new, persistent cough is being told to stay at home and self-isolate for seven days. Many observers were surprised that the guidance did not go further.

For example, until Thursday night, England's domestic soccer competition, the Premier League, was the only major league in Europe still going ahead without any disruption. It took an elite-level coach, Arsenal's Mikel Arteta, to test positive for the virus for officials to call an emergency meeting which led to a suspension of matches Friday until at least early April.

Contrast this with the United States, where there have been widespread cancellations, from Broadway to the NBA. Some American schools and colleges have shuttered, and President Donald Trump has imposed sweeping international travel bans and declared a national emergency.

Empty shelves in the toilet roll/kitchen towel aisle of a supermarket in London on Friday as consumers worry about product shortages, leading to the stockpiling of household products due to the outbreak of the new coronavirus. Justin Tallis / AFP - Getty Images

In Italy, the worst-hit country outside of China, public life has all but shut down, with bars and restaurants closed for two weeks and police issuing fines to anyone caught in certain areas without good reason.

Across Europe, from France and Germany to Norway and Ireland, schools have been closed, sporting events have been canceled.

Britain has taken a different tack.

Sir Patrick Vallance, U.K.'s chief scientific adviser, defended the government’s strategy Friday, telling the BBC that instructing people with a cough or a fever to self-isolate would have the “biggest impact” in tackling the coronavirus.

Vallance said people were more likely to get infected from a family member or a friend in a small place than in a big place with lots of people. And asked why the government hadn't shut down schools, he said the role of children in spreading the disease was "less clear."

“It’s inconceivable that those children are not going to mix anyway and, of course, many of them may be sent to be looked after by their grandparents during that period,” he added.

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Vallance told Sky News said the government hoped to create “herd immunity” in the U.K. to protect the country from future outbreaks. He said achieving this would involve around 60 percent of the U.K.'s 66 million people caching the virus.

"Communities will become immune to it and that's going to be an important part of controlling this longer term," he said.

Not all British health experts and policymakers agree with the government’s assessment of how to tackle the outbreak.

A "Do Not Enter sign" and National Health Service information about the coronavirus is displayed at the entrance to a doctors surgery in north London on Friday. John Sibley / Reuters

“The U.K. is on the edge of an avoidable calamity,” tweeted Richard Horton, the editor-in-chief of The Lancet, a general medical journal.

"Read the Italian experience. There are critical lessons here that the UK government either isn’t aware of or is ignoring," he said.

"We need immediate and assertive social distancing and closure policies. We need to prepare the NHS. This is a serious plea," he added, referring to Britain's much-beloved National Health Service.

Former Health Secretary Jeremy Hunt also criticized the government’s strategy.

“I think it is surprising and cornering that we’re not doing any of it at all when we have just four weeks before we get to the stage that Italy is at,” he told BBC’s Newsnight program Thursday.

“You would have thought that every single thing we do in those four weeks would be to slow the spread of people catching the virus.”