What is the UK government's strategy now?

UPDATE, 24 March: I have refined my estimates of how long controls will last here.

John Butters, 22 March 2020

Summary

I think there has been a public policy shift in the UK in the past week or so. Previously, the COVID-19 strategy was “mitigation”, which means allowing the virus to move through the population and managing the load on hospitals. Last week, the strategy appears to have shifted to “suppression”, which means taking tough measures to control the virus. I guess this could take 3-5 months. I think this strategy makes sense if combined with intensive testing and contact tracing after the suppression period is over.

This is informed speculation. I am not a medical scientist and have no better access to information than anyone else. I am trying to get my mind around what could happen in the future. Please follow published medical guidance from the proper authorities to guide your own actions.

What has been happening in the UK?

On 3 March the government published a paper outlining its planned response to the COVID-19 outbreak. The first phase was “contain”, trying to contain cases as they were detected and prevent the virus from spreading. When it became clear that containment was not working, the government moved to the next stage, “delay”, which involved using measures such as school closures, encouraging home working and reducing large-scale gatherings to lower the peak level of infections and push the peak into the summer when hospitals are less busy. The next stage after that was to have been “mitigate”, which involved tweaking hospital resources, for example by early discharge of patients and delay of non-urgent care, in order to help hospitals to cope.

Events have overtaken this plan, which I shall call “the original plan”. The COVID-19 virus turns out to be more infectious and more dangerous than was previously understood, and in mid-March that became clear. In response, it appears the government has abandoned the original plan and turned to stronger measures to contain the virus. This piece tries to understand why the government has acted as it has, and then to use that understanding to answer the most important question for the economy: how long will this go on?

What is the new plan?

Prime Minister’s statement

The government has not published a new plan, but we know that it has imposed much stronger measures to ensure social distancing, including the closure of all public meeting places, after receiving advice from scientists at Imperial College. We also know what Boris Johnson said on 20 March: that the “ambition” is to “turn the tide” against the coronavirus in three months and eventually to “stamp it out”. He listed testing, new medicines and digital technology as important means to that end. We can use these facts as a framework to make a guess at what those in government are thinking.

Why abandon the original plan for stronger social distancing?

To answer this question, the key thing to understand is what the scientists at Imperial College said to the government to cause a change of plan. They published a paper setting out their advice on 16 March (my summary here and summary of responses here). This paper is pessimistic. It says that in light of what is now known about the virus, even a strong version of the original plan would have meant 250,000 deaths and intensive care wards being overwhelmed many times over. Moreover, 250,000 deaths could be an under-estimate because the analysis does not take account of (i) ordinary emergency cases receiving poorer care, (ii) medical professionals becoming ill and (iii) the death rate being higher in people who are not treated because hospitals are too busy. So, under the original plan the situation would have got very bad indeed. That is why “mitigation”, the idea of allowing the virus to infect everybody while slowing it down, has been abandoned.

What were the alternatives?

That explains why “mitigation” has been abandoned, but not why “suppression” has been adopted instead – because the Imperial paper is also pessimistic about that. It says that the virus can indeed be suppressed by strong social distancing measures, but it simply bounces back when controls are lifted, potentially pushing the disease peak into late autumn. The government could reimpose controls every time a bounce-back started, but that would mean controls were nonetheless in place most of the time and the outbreak would still be going strong after two years, which it seems reasonable to assume would cause appalling damage to the economy.

In other words, the Imperial advice presented the government with an impossible decision. One the one hand, the softer “mitigation” strategy would mean hundreds of thousands of deaths. On the other, the harder “suppression” strategy would work, but there is no way to get out of it once you have started: to keep hospitals from being overwhelmed, controls have to last for years. One might hope for a vaccine, but medical science is not a certain process and while there are hopes for a vaccine in 12-18 months, we could have to wait much longer. In sum, the Imperial paper suggested that there were no good options.

However, it appears that the paper was too pessimistic about the prospects for “suppression”. South Korea has controlled its epidemic without locking down cities by heavy testing of the population and technology-driven tracking of social contacts. The country’s health system was prepared for a quick epidemic response because of its experience with the MERS virus in 2015. Hong Kong, Singapore and Taiwan have successfully used the same approach. Statistician Nassim Nicholas Taleb and colleagues argue that measures like this, together with door-to-door monitoring of cases, could be used after a “suppression” strategy is ended to control the inevitable new outbreaks of the virus – meaning that “suppression” does not have to have to last for years after all, but only a few months. The Prime Minister’s emphasis on testing and using digital technology to monitor cases suggest that this is what he is thinking as well. The government’s new plan is probably to halt the epidemic in its tracks with “suppression”, and then stop the virus from bouncing back with widespread testing and close tracking of people with whom the infected have met.

Government plan

Allow me to summarise my best guess at the government’s new plan.

Stage 1 is to bring the outbreak under control with three months of strong controls, keeping people at home as much as possible (helped by closing restaurants and other social venues, closing underground stations and no doubt further measures). Experience from China suggests that the growth rate of new cases will fall when lockdowns are imposed. Stage 1 will also buy time for (i) more testing kits and ventilators to be acquired, (ii) testing and tracking methods to be improved and (iii) the population to acquire the habits of social distancing, such as washing hands, avoiding door knobs and so on.

Stage 2 is to employ heavy testing and technology-enhanced contact tracking to control further outbreaks on the “suppression” period is over. This effort will need to continue for some time because, sadly, the COVID-19 epidemic is likely to continue in other countries so new cases will continue to come into the UK.

The Prime Minister also mentioned new medicines, but at present we have only preliminary indications of what might be effective. I plan to write a further piece on the most promising treatments. The emergence of a good treatment would obviously help to reduce the number of deaths in Stage 1 or Stage 2.

Scenarios

Assuming this is actually the government’s new plan, we can use it to think about what could happen next.

1.   The argument that social distancing will bring a run-away epidemic under control is based on the Chinese experience. The UK’s methods are not as draconian. What happens if they do not work? Given that the government will be highly motivated to avoid hundreds of thousands of deaths, it is most likely that legal measures to force social distancing would be introduced, as they have been in other countries. I guess it could take a month to get to that point and that the growth of the virus in the interim would mean controls had to be extended for another month, adding two months to Boris Johnson’s 3-month timescale. I therefore make an educated guess that the “suppression” stage could last 3 to 5 months.

2.   The government is planning to ramp up testing for the virus to 10,000 tests a day as soon as possible and to 25,000 a day within 4 weeks (from 19 March). However, epidemiologists do not seem to think that this would help with “suppression” very much. Testing is about stopping a resurgence of the virus once the outbreak is contained. So my guess of 3 to 5 months is not reduced by the planned increase in testing.

3.   Stage 2, the process of using testing and contact tracing to prevent the virus bouncing back after it is “suppressed”, could fail. This would be a bad outcome, because it would take us back to the impossible choice between many deaths on the one hand and long-term suppression with unimaginable economic damage on the other. At the moment failure of testing and contact tracing seems unlikely because the approach has worked, so far, in several countries. We can keep track of how it is doing on an ongoing basis by tracking case numbers in Korea and Taiwan.

Market implications

If my guess above is indeed the government’s new plan, and if it begins to work, and if a similar approach is used across the rich world, then stock markets could start to recover as soon as the plan comes to be widely adopted and understood in the rich world. Markets could then rise further if “suppression” seems to be working – as long as case numbers do not start to rise again in large economies that are already controlling the outbreak with testing and contact tracing, because it is essential that those work in order to prevent the virus bouncing back later this year.

UPDATE, 22 March: Since I wrote this, Boris Johnson has threatened to impose lockdowns if people do not get better at social distancing. He is moving faster than my guess below in that regard. Perhaps that means we should plan for a 3 to 4 month period of strong controls rather than 3 to 5 months.

UPDATE 2, 22 March: WHO assistant director general Bruce Aylward has said that testing was key to getting the epidemic under control in China. That is both good and bad news: good because it suggests that testing will help when it begins, but bad because not enough testing can be done now and there will be a lot more tests to do if the virus has spread to a larger number of people.