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Why Boris Johnson Reversed Britain’s Virus Response

The U.K. government’s gradualist approach to fighting the virus unnerved many scientists. New modelling suggests it was wrong.   

Why Boris Johnson Reversed Britain’s Virus Response
Boris Johnson, U.K. prime minister, front right, Rishi Sunak, U.K. chancellor of the exchequer, left, and Patrick Vallance, U.K. lead science adviser, arrive for a daily coronavirus briefing inside number 10 Downing Street in London, U.K. (Photographer: Matt Dunham/AP/Bloomberg)

(Bloomberg Opinion) -- Flanked by his chief medical officer and chief scientific adviser Monday afternoon, Boris Johnson didn’t so much announce an escalation in the government’s response to the coronavirus crisis as signal a sharp course correction.

Exactly why the government has changed direction was confirmed some hours later, when the Imperial College Covid-19 Response Team, whose epidemiological modelling helps inform U.K. policy-making, published a bombshell report on its findings with implications for both Johnson and U.S. President Donald Trump. If either follows the logic of the report, there are far more stringent measures to come and long-term implications we’ve only begun to contemplate.

The 30-member Imperial team set out two fundamental strategies in dealing with Covid-19: “mitigation,” in which the aim is not to entirely disrupt transmission to but slow its impact; and “suppression,” which aims to reduce the rate of transmission so dramatically that each case generates less than one additional infection and the disease is stopped in its tracks. You can guess which path China followed once it came to grips with the fact it had a massive crisis on its hands. The U.K. government’s policy up to now, which it called the “delay” phase, adopted a weak mitigation policy at best.

You can measure the difference in lives. With no mitigation measures at all, the Imperial Team said they would expect 80% of the population to be infected, resulting in 510,000 deaths in the U.K. and 2.2 million in the U.S. — and that’s without accounting for the impact on mortality of health systems getting overwhelmed. By the second week in April, the critical care capacity of Britain’s National Health Service would be overwhelmed.

Even with more optimal mitigation measures, including many of the new measures Johnson announced Monday — self-isolation for anyone with symptoms and their family members for 14 days, longer term isolation for the elderly and vulnerable, and asking the general public to refrain from non-essential travel — peak demand on critical care beds will likely be eight times the capacity of Britain’s medical system. And for those insisting that the U.S.’s private care model is somehow better equipped, afraid not — the gap is the same.

Mitigation, in other words, would overwhelm our health-care systems and lead to hundreds of thousands of deaths. Suppression is more draconian, but also more effective. Suppression measures include social distancing of the entire population, strict isolation of infected cases, household quarantine, school and university closures.

But suppression at this stage of the epidemic comes with a catch: It will need to continue until a vaccine is found or what’s called herd immunity is achieved, whichever comes first, say the authors. The former is estimated to take 18 months, though perhaps the urgency and the ingenuity of global teams working on the problem will accelerate that. Herd immunity — when enough people have been infected so that the virus stops spreading — depends on the transmission rate of the virus. Since Covid-19 is highly infectious, a much greater share of us have to get it for it to stop spreading. One estimate bandied about is 60%, though in an article for the World Economic Forum, Jeremy Rossman, an honorary senior lecturer in virology at the University of Kent, calculates that 70% of the population would have to be infected for herd immunity to work.

What happens if restrictions are lifted too early? Short-lived suppression is likely to result in a resurgence of the virus. Health systems would again be overwhelmed, though presumably further capacity could be built in the meantime. That is something epidemiologists will be watching closely in China, Italy and other countries that are some ways ahead on the curve.

It’s not easy to say with precision what a particular combination applied at a certain point on the epidemic curve will achieve. Nevertheless, the authors conclude that the more suppression measures the better, and the measure that has the largest overall impact is social distancing applied to the entire population. And while there has been much debate over the wisdom of school closures, the authors recommend them since they break the social contacts between households and so reduce transmission.

Suppression, the authors found, is “best triggered early in the epidemic.” In the U.K., there are now questions as to whether that ship has already sailed. Similar ones can be raised about the U.S. response too.

We have been hearing for a while about the low mortality rates of Covid-19 as if mortality rates are somehow independent of the health-care systems treating those who need hospitalization. On the contrary, how many people die from Covid-19 (which is surely the single, most important measure of government policy) is directly related to how many of the very ill have access to intensive care beds. That, in turn, depends on how rapidly and for how long the government can forestall the spread of the virus: In other words, going early and going hard saves lives.

In Lombardy, 16% of all those hospitalized required intensive care treatment, according to an article on ICU admissions by three Italian doctors published last week. The Imperial study breaks down ICU patients by age group. The percentage of hospitalized cases requiring intensive care jumps from 6.3% in the 40-49 age group to 12.2% in the 50-59 age group and 27.4% in the next decade of life.

All of this helps explain the sudden change on Monday. “In the U.K., this conclusion has only been reached in the last few days, with the refinement of estimates of likely ICU demand due to Covid-19 based on experience in Italy and the U.K.,” the authors write. Previous estimates assumed only half the demand for respirators now assumed. “We therefore conclude that epidemic suppression is the only viable strategy at the current time.”

Many people did not need the academic model to draw similar conclusions. Whether they reacted swiftly to the coronavirus (Singapore, Israel) or with a delay (China, Italy), a consensus protocol had formed around a policy of testing widely and taking fairly drastic action, because that has been shown to be effective. And yet the U.K. government claimed its approach sought to “flatten the curve” of infections (or squash the sombrero, in Johnson’s more colorful phrase) with a different policy. The government limited testing mainly to hospitalized patients and those severely ill, encouraged schools to stay open, and adopted minimal self-isolation guidelines.

On Saturday, hundreds of scientists published an urgent open letter warning Johnson he was heading toward a health-care disaster and urging the government to take “additional and more restrictive measures” immediately, in line with countries around the world. Former Conservative Health Secretary Jeremy Hunt said it was “surprising and concerning” that Britain was not following other European countries in imposing certain restrictions. It’s fair to say there was a lot of discomfort with taking a gradualist approach when other countries were finding shock therapy was what worked.

Johnson’s decision to brief the public daily is an important acknowledgement that the only way the government strategy can work is if there is a large degree of public buy-in, and that includes the medical and scientific communities. Trust in government has been so damaged by three years of Brexit infighting that many suspect they are being misled or manipulated even when it’s not the case.

Johnson will now have to spell out where the U.K. is on the mitigation-suppression scales, and exactly how far the government is willing to go to keep mortality rates down. And he will have to order his chancellor of the exchequer, Rishi Sunak, back to the drawing board; last week’s budget is woefully out of date. If the updated models are correct, either we’ll need a very fast vaccine or the U.K. economy too will need a respirator.

To contact the editor responsible for this story: Melissa Pozsgay at mpozsgay@bloomberg.net

This column does not necessarily reflect the opinion of Bloomberg LP and its owners.

Therese Raphael writes editorials on European politics and economics for Bloomberg Opinion. She was editorial page editor of the Wall Street Journal Europe.

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