You may be as confused as I am as to why the UK government seems to be taking no or little action regarding the current covid-19 pandemic. In this video, Prof. Chris Whitty – the current chief medical officer – explains the strategy and the science behind the government’s reasoning. Prof Whitty happens to be an epidemiologist and, in fact, an expert on viral transmission. He has a very good publication record. He is what some would call “an expert”.
The video is fairly long so I am going to summarise its key points and then draw some conclusions.
The CMO believes that the mortality rate for the disease is not higher than 1% – and that 1% is most likely the top estimate. This is mostly based on the data we have from China. The mortality rate or CFR represents the fraction of people who died after having contracted the disease. This number relies on our estimate of the denominator. Worth mentioning that the WHO currently work with a CFR estimate of 3.4%
The UK Government works on a line where they expect at least 20% of the population to become infected; the reasonable worst-case scenario is 80% (which is the theoretical maximum – you never reach 100% for reasons of herd immunity). Their working hypothesis is somewhere in the middle. The reader can do the math of what 1% of 50% of 60 million is to estimate the number of deaths the UK expects.
The UK will act through four reacting measures, which will all co-exist at the same time but with different weights, according to the need: contain, delay, research, mitigate. Contain means we will try to keep the viral agent out of our territory; delay means we will slow down its geographical presence; research means we will study how the virus works and how it can be stopped; mitigate means we will slow down its temporal diffusion. We are now at the transition between “contain” and “delay”.
Social containment actions (i.e. the “mitigate” phase) will be postponed as much as possible in order not to interfere with people’s life and the economy. These are the actions Italy and other EU countries have decided to take right now – the ones we see in the news. The CFO believes some mitigating actions (such as closing schools) have low efficacy and should not be considered at all. In fact, CFO says that there are only two scenarios that will lead to school closure: one – very unlikely – in which teachers get massively exposed to the virus to the point schools lack personnel; a second one, where HMG wants to show they are doing something (I am reading between the lines but it’s quite clear that’s the message). CMO believes that, unlike for the flu, school closure would be highly unimportant for stopping the disease. This is based on the observation that children are highly resistant to the virus and its symptoms.
The CMO recognises China has done a great job containing the infection but believes their infection rates may come up again after China releases the brake. (I am partly sympathetic with this observation and my feeling is that this point is critical to understanding the strategy). What the UK does not want is to apply mitigating measures that have an impact on society and the economy only to then discover the virus is coming back as soon as their measures are released. Instead, they are interested in letting the virus go through its course, albeit slowly (note: this is probably what BoJo meant when he said “we should take it on the chin”)
The CFO is clear it will take at least 18 months to see a vaccine. Instead, greater interest should be placed on the repurposing of old or currently approved drugs.
One of the most efficient measures from the epidemiological models that the Government is currently considering is to isolate elderly people from the virus. Obviously, this also means isolating the same people from society which has a cost in terms of mental health. To reduce this latter damage, the UK will delay isolation measures as long as possible. In short, the entire procedure will not look like a 100m race but rather like a marathon which is why the last stage, mitigations, should start as late as possible. To put things into perspective: the Italian PM is currently asking Italians to bare with the situation for two weeks, saying this investment will allow everyone to go back to normal life soon. The UK, on the other hand, is looking at acting milder measures but in the spectrum of months.
What does it all mean
1) There is a very important difference between what the UK plans to do and what Italy or China has decided to do. The UK will be treating this like the flu and let it run through in one wave. What they want to avoid, is to introduce very severe social actions with a potentially crippling economic cost, only to see the infection come back again as soon as those actions are released. Importantly, the WHO recommends against adopting the UK procedure and invites to take China and South Korea as examples to follow. Mike Ryan, of WHO, today clearly advised against this approach. To paraphrase, he said: “Stop approaching this like the flu: the flu can not be controlled. China and S. Korea have demonstrated that COVID-19 can be controlled.”
Obviously, both sides are taking a gamble.
2) A great deal of UK planning relies on information we got from China. There is the possibility this information is not correct because the demographic is different. The UK government should take more attention to what is happening in Italy and Germany because those demographics are more alike. I also have the impression the UK is heavily underestimating the Chinese health system or perhaps overestimating the NHS capabilities. Lombardy has one of the best public health services in the world and yet they are in dire straits.
3) The British approach seems to be very dry and pragmatic (I can speculate why this is so and it would involve N10’s special advisor – but this would be just speculation). This may not necessarily go down easily with the public unless their gamble immediately pays off. In short, it will all depend on what will happen to places like China, Italy or South Korea within the next two or three months. Will they be able to truly contain the infection or will the coronavirus come back in April or May?