Wednesday, March 18, 2020

How they got it so wrong - a theory

Think I will restrict the coronavirus stuff to appearing here, it's not really our professional work at and I only posted there because of the Rmarkdown to Wordpress publishing thing which isn't actually as useful as I'd hoped it would be.


Recent events have got me thinking - how could the Govt have got it so wrong with their COVID-19 strategy? What has changed (if anything) in the science, and their response? And what should they actually be doing? Especially in light of the research published a couple of days ago, which seemed to merely state the obvious. The Lancet editor Richard Horton has been tweeting critically (eg quoted in this post) and wrote this article in the Guardian:
Indeed, it didn’t need this week’s predictions by Imperial College scientists to estimate the impact of the government’s complacent approach. Any numerate school student could make the calculation. With a mortality of 1% among 60% of a population of some 66 million people, the UK could expect almost 400,000 deaths. The huge wave of critically ill patients that would result from this strategy would quickly overwhelm the NHS.
The UK has a long-standing pandemic plan - specifically for flu, but while COVID-19 is technically not flu, it is a respiratory disease with strong similarities. The UK has gone through a number of flu pandemics, as recently as 1957 which many of the older generation (including my mother) remember well. 

It is explicitly baked into the strategy that 
Stopping the spread or introduction of the pandemic virus into the UK is unlikely to be a feasible option 
 (Appendix 1, here)

While the plan does mention as many as 750,000 deaths, it may be that people didn't really think that sort of figure was plausible. A few tens of thousands maybe, a bit worse than a normal bad flu year, but hardly existential. So, the basic paradigm seems to be, the govt only ever considered the possibility of the epidemic running through the population, killing as many as it happened to, according to its specific parameters for spread and lethality. Strategies for controlling the epidemic at a lower level, to eliminate it before it burnt itself out, just weren't in their solution space.

Hence, “taking it on the chin ” and “herd immunity”. That's just what we do, cos that's what we have always done, cos that's how these things work. The pandemic plan considered the necessity of dealing  with the excess deaths, and things like how to reduce the spread to some extent (social distancing and cocooning of particularly vulnerable people are beneficial strategies, albeit with limited effect). But it just never considered whether it might be appropriate to stop the disease entirely. 

But actually, when you do the sums, you see that a death rate of 1% (and I'm getting bored of pointing this out, but this estimate is only valid when the incidence of illness is low and victims get good healthcare!) occurring over a time frame of a couple of months is horrific and will see piles of bodies in mass graves, with the NHS totally overwhelmed in the meantime. And we also see from other countries that an alternative approach is possible, one in which stricter controls on social mixing, combined with more aggressive testing and quarantining of contacts of cases, can actually control the epidemic. The key is in whether we can get R0, the basic reproductive rate of the virus, below 1 or not (and keep it there on a sustainable basis). If we can, then we can beat the disease with only a few hundred or thousand deaths, rather than hundreds of thousands.

So that's my theory as to what “changed”. It wasn't the science of the disease. It was the demonstration of an alternative solution, one in which the epidemic is controlled at the outset. If the epidemic had simply overwhelmed China first, before spreading across the world like a dark cloud, swamping nation after nation as it did so, maybe we would have all accepted that a moderate percentage of the population were going to die, and the rest of us would pick up the pieces afterwards. But we've now seen that this is not inevitable, and it seems awfully defeatist to not even try to do better.

1 comment:

Dan said...

I suspect Italy's example also played a role. China and others showed that remediation could make a difference, Italy demonstrated the risks of counting on adaptation.