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Was there a better approach to tackling the spread of SARS-CoV-2 (virus that causes COVID-19 disease) across Western countries, especially the UK and US? Last week, I challenged the notion that science was immutable, dictating only one path. And I had my doubts about the British government’s softly-softly approach.
All that changed yesterday with a shift in strategy delivered by a persuasive Boris Johnson. For more details of how this emerged, read Alex Wickham’s eye-ball popping report after this essay.
A new paper produced by Neal Ferguson and colleagues at the MRC Centre for Global Infectious Disease Analysis essentially argues that the mitigation strategy that Johnson-and-crew were recommending last week was ten times worse (in terms of deaths) than a suppression strategy. The paper is readable and in the interests of being an informed citizen, of any country, I suggest you do. Ultimately, it is about needing to go further than “flattening the curve”. (As I pointed out in #261, we need to think harder than just flattening the curve.)
It isn’t just about the dead
The balancing act for any government is not simply driven by the number of deaths. It is a systems problem, and actions need to prevent the “system” collapsing, whether that is the health system collapsing, the economy collapsing or civil society collapsing. Deaths are tragic. Then they become statistics.
But they are also an indicator of the overall health of the system.
Ferguson identifies two strategies to tackling the pandemic:
(a) mitigation, which focuses on slowing but not necessarily stopping epidemic spread – reducing peak healthcare demand while protecting those most at risk of severe disease from infection,
(b) suppression, which aims to reverse epidemic growth, reducing case numbers to low levels and maintaining that situation indefinitely.
This is the key chart in Ferguson’s modelling of mitigation, which qualitatively applies to the United States and the UK.
The red line is the surge capacity of critical care. As you can see, even under heavily mitigated strategies like the blue line, our surged capacity is exceeded by mid-April. The mid-June peak still represents a demand for critical care beds that is eight times higher than our surge. So for every 1 patient in a critical care bed, there are about 7-8 in urgent need queuing up from coronavirus. (Not to mention routine operations independent of the disease.)
This model (and remember Box’s edict, “all models are wrong, but some are useful”) shows that aggressive mitigation could reduce a death toll by about 50% on a pure numbers basis. The paper doesn’t describe how unmitigated those deaths would be. Most of them would not occur in the critical care bed, but wherever they happened, in the corridor, parking lot, tent, requisitioned hotel room.
“Given that mitigation is unlikely to be a viable option without overwhelming healthcare systems, suppression is likely necessary in countries able to implement the intensive controls required,” says Ferguson. Suppression involves much tougher controls and compliance than mitigation.
The top chart shows the full scale for demand on critical care beds, zoomed in on the lower chart.
Suppression may be better for a condition like COVID-19 because the virus that causes it can spread at least two days before symptoms are noticed. Even with perfect testing, this asymptomatic spread is problematic in mitigation approaches.
Two strategies of suppression seem to work best. The brown one (case isolation, quarantine and social distancing) and the green one (brown + closure of schools and universities.)
They both limit immediate pressure early in the pandemic, but store it up for the autumn time. At this level, all other things being equal, brown beats green if you can build up enough critical care capacity in a furloughed economy by the middle of April. (Can you produce enough medical supplies and devices, and train enough nurses and doctors in the next four weeks? Medical schools in the UK are, I hear, accelerating graduations of the summer class.)
But what happens in October?
One dose of suppression just buys us time. It pishes the curve out. To smash the curve we need to do more.
The team suggests adaptive triggering of suppression strategies. That is, when it looks like we have the current wave of the epidemic under control, as measured by the decline in ICU admissions, we can relax social controls. And then ICU admission starts to rise, it becomes an indication that the virus is spread again, so we regulate its spread by turn on suppression policies.
In this two year forecast, the blue boxes represent the time when suppression is in place. Two years should be long enough to find a vaccine and innoculate the population, providing “herd immunity” through more humane means.
The outcome of this approach would be to reduce deaths by 85-91% and crucially in many scenarios to never exceed our current critical care capacity for more than a short duration. Table 4 in the paper lays off a range of trade-offs.
The problem is that we’ll need to spend anything like 58-90% of the next two years in a state of on-and-off case isolation, quarantine, social distancing and school and university disruption.
And we’ll need to be able to resolutely switch into “suppression mode” for weeks at a time, like an extended wet-break at school. Well, not like that, more like one of those science fiction movies where the sun pulses dangerously once-in-a-while and we have to scurry indoors for weeks to avoid being scorched.
This also means communicating why and when we move into “on” and “off” modes. In the UK, the government didn’t do a great job communicating their strategy last week as I wrote here. In the US, the communication challenge may be more extreme.
Capacity, adaptation and resilience
I said that this isn’t just about deaths and beds. It is about the system. So let’s imagine some things we can do under a suppression strategy. The first is we need to buy time. We need to buy time in order to start to adapt. Every day or week of space that is created is an opportunity to build adaptations (provided that time is frittered in front of Netflix). Those adaptations might be technical (like 3-d printing ventilator parts) or they might be social (like establishing a neighbourhood wellness scheme to check on those in your community.) But they take time to set-up. And take it takes many iterations to learn how to do them well.
Time allows us to build capacity in the system. In the UK’s case, this means, inter alia, increasing our critical care beds shown by the black dotted line, in my annotated chart above.
We currently have a fifth the number of critical care beds as Germany, according to the OECD. It would certainly mean increasing our COVID-19 (or other disease) testing capacity. Singapore is a decent benchmark.
Capacity could also mean better front line protocols for detection and personal isolation. Better more widespread detection means more isolated quarantines and less widespread disruption. This can be low tech. Mumbai airport is stamping people who need quarantine with semi-permanent ink.
Experts have gone on to stress the importance of “testing, testing, testing” to quote Tedros Adhanom.
If you know precisely where the cancer is you can hit it with a gamma knife. If you don’t, you need to surge the whole body with radiation. So to Sars-COV-2 running amok our nations. If we know where it is, we can isolate those people affected.
We can also build capacity “in the system” to handle surging a completely different usage pattern of broadband, electricity and water for which the systems were designed. It might include our capacity for the consumer economy to function without large malls and supermarkets, whether that is more local shops or home deliveries.
It also gives us time to adapt to new systems of managing threats like this. Taiwan seems like an exemplary case of pandemic alertness and systems which can operate to allow freedom—even for those with suspected COVID-19. Despite it’s proximity to China and a high-density urban agglomeration, Taiwan only has 67 cases of COVID-19. (Tapei’s population density is double London’s; Taiwan’s population density is seven times that of the US.)
Neither the US or the UK can wholesale copy Taiwan’s strategies, but there are several that could be of interest. (Sorry, I don’t have time to go into it here, but I have spoken to people involved.)
Much adaptation will be social. Hugging and handshaking less. Working from home more. Washing hands and being cleaner around the house. Changing our patterns of play, socialising, worshipping and more. (My earlier essay Six ways Coronavirus will change the world missed most of the meaningful changes to our habits and daily lives of which there will be plenty.)
Some will be technical. Could we create a Fitbit-style app that tracks your social interactions for you and prompts you if you are meeting too many new people? Better, it also tells three of your friends so that they can apply social pressure on you to comply more effectively. (That is just my dumb idea, many better ones are floating around, like this one.)
There are other innovations we could bring to bear to help us all contribute to reducing the spread. Could high-risk venues like places of worship or conferences adopt more stringent policies to enable contact tracing and case isolation? (Again, just one idea of thousands.)
Our economies will need to adapt. One example, airline staff not be needed in such numbers. Do they retrain for the burgeoning nursing and care market? They know how to work in complex patterns and deal with people from all walks of life. What can pilots, used to managing complex mission-critical systems, turn their hands to?
And beyond adaptations for a war-like mobilisation, how do we start to adapt our ways of life to build some joy into them? How do we adapt so we move beyond fear into thriving kindly and sustainably?
We now need to invest in a culture of resilience. Last year I spent some time with General Sir Richard Barrons who used to run Britain’s Joint Operations Command. We talked about resilience at one point. He said:
We’ve had a really lovely period in the history, particularly, of the West, where, since 1989, no one has had any thought, in the UK or Germany or France and many other countries, of existential peril. There was no sense of invasion or civil war or harm from a profoundly challenging natural disaster, and that’s allowed us to spend our money on other things, a much better social offer to ourselves. This has accentuated this millennial sense of it’s all about the individual and perfect freedom to lead your life, really without commitment or expectation, or any sense of harm.
That period is now over, and partly because of the way the strategic context is changing, partly because of the way technology is changing, we have to come to terms with the fact that we in the West exists as strategic snowflakes now, where our daily life is enormously fragile.
One huge challenge is that the suppression model is very brittle and demands a high level of compliance. For some, like these British tourists, compliance may require a bit more duress. Complying to the suppression strategy will be boring, tedious, not fun… not great for ‘strategic snowflakes’. However, we’ll need to comply to help each other comply.
The time we buy needs to go into building resilience in our systems. But being unedifyingly zeroed on “shareholder value”, airlines have no resources to support themselves through this hiccup. About 96% of their free cash flow from the last decade went on share buybacks.
Centralised systems also need to be complemented by more decentralised ones whether in energy production, food production, ability to live one’s life in a short radius if need be. Decentralisation drives resilience, albeit at the cost of centralised control. We’re ready for more decentralisation now—the technologies support it.
All this buys us time. It buys us time for the Hail Mary passes we need.
It could be the invention of a brilliant, accurate, at-home test that works pre-symptomatically. It could be a success with treatment, like remdesivir. It could be the arrival of summer and the possible reduction of the virus’s potency.
Or it could be the ultimate 80-yarder, a vaccine.
Amazingly, one is already in testing, less than three months into this global spread of this disease. (Watch Jennifer Haller being injected here.)
Ferguson’s paper on suppression strategies, which triggered this letter, is instructive. There are paths we can take that have different, better outcomes, provided we use the time these tough approaches give us wisely.
Even finite, time is wonderful. It gives us a chance to try new things out until we beat this thing.
I’m mindful of the words of American Army colonel, Hal Moore:
There’s always one more thing you can do to influence any situation in your favor—and after that one more thing, and after that…. The more you do the more opportunities arise.
Keep your distance, check-in on someone and WASH YOUR HANDS***.
If you want to comment, please comment on this essay not by replying to the email. Due to the volume of email we can’t really get to replies.
***Please go and wash your hands with soap and water for 30 seconds.
Thanks to Marko Ahtisaari, Paola Bonomo, Vishal Gulati, Nicolas Granatino, Marija Gavrilov and Hampus Jakobsson for ideas and comments.