From Mitigation to Suppression: U.K. Gov Changes Its COVID-19 Response

Mitigation, the initial policy of the British government, would thus overwhelm the U.K. health-care systems and lead to hundreds of thousands of deaths.

The Imperial Team says that suppression is more draconian, but more effective. Suppression measures — social distancing of the entire population, strict isolation of infected cases, household quarantine, school and university closures – comes with a catch, though: To be effective, it must continue until either a vaccine is found or herd immunity is achieved.

The development of an effective vaccine is estimated to require 12-18 months, although the pace may be accelerated by intense, collaborative scientific work.

The achievement pf herd immunity depends on the transmission rate of the virus. COVID-19 is highly infectious, so at least 60 percent of the population must be infected before herd immunity is achieved. Some experts argue that 70 percent of the population would have to be infected for herd immunity to work.

Supporters of mitigation argue that suppression unnecessarily slows down the rate of infection among healthy segments of the population, thus unnecessarily delaying the achievement of herd immunity (see Tom Solomon, “Coronavirus: The U.K. Approach Explained,” HSNW 17 March 2020).

The Imperial Team is clear in its recommendation of suppression, saying that the more suppression measures the better, and that the most effective measure, with the largest beneficial health impact, is social distancing applied to the entire population. Young children are less susceptible to infection, but the Imperial Team recommends school closures since they break the social contacts between households and so reduce transmission.

Suppression, the Imperial Team says, is “best triggered early in the epidemic.”

This was not the initial choice of the British and U.S. government. In the U.K., the choice of mitigation over suppression was the result of a specific medical philosophy, and a decision to adopt the recommendations of some experts over the different recommendations of other experts.

In the United States, the botched response of the Trump administration owed more to incompetence, confusion, and in-fighting, and a dissembling and disruptive president who kept getting in the way of his administration’s own experts.

In both countries, there are now questions whether the train has already left the station.

Reports about the U.K. government’s change of direction (see The Times; The Telegraph; New York Times; Le Monde)

The Imperial Team highlighted the benefits of going early and going hard saves lives. In Lombardy, 16 percent of all those hospitalized required ICU 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 percent in the 40-49 age group to 12.2 percent in the 50-59 age group and 27.4 percent in the next decade of life.

“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.”

In other words, the more gradualist mitigation approach, which was the initial preference of the U.K. government, could not offer a guarantee that vulnerable segments of the population (that is, the elderly, and those with certain underlying conditions) could be effectively isolated from the less-susceptible segments of the population, where the spread of the virus would contribute to achieving herd immunity more quickly.

In the absence of such a guarantee, the mitigation approach ran the risk of overwhelming the U.K. health care system with infected people requiring medical attention, leading to tens of thousands of deaths.

 quickly  

“Many people did not need the academic model to draw similar conclusions,” Raphael writes.

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.

Last Saturday, hundreds of scientists published an urgent open letter to warn Boris Johnson that the U.K. was heading toward a health-care catastrophe, and called on the government to take “additional and more restrictive measures” immediately, in line with countries around the world.

Raphael writes that “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.”

She adds:

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.