Boris Johnson said we should take the coronavirus ‘on the chin’ and count on ‘herd-immunity’. This, he claimed, is what his scientific advisers recommended.
I find this very hard to believe and have many doubts and questions.
To start with, I doubt that this is what Johnson’s scientific advisers recommend – it is a solution that SOME of his scientific advisers recommend. And it is a solution that seems easy to follow. It is, however, by no means the only strategy for tacking the pandemic; it is just one of several options.
The fact that all other countries have opted for other solutions, suggests to me that it is an unusual path to go down to. The modellers who obviously like it had to make a number of assumptions; that’s what modellers always have to do and rarely tell us about. But what if not all of these assumptions are correct?
The herd-immunity strategy counts on the fact that, once a certain percentage of the population has taken the infection ‘on the chin’, it is immune and therefore the transmission of the virus within such a population will be dramatically reduced or even zero. The percentage of the population needed for that to happen depends on how contagious the virus is. For the measles virus, herd immunity requires 90% of the population to be immune. For the coronavirus, the figure is said to be 60 – 70%. Is that an assumption or a fact? If it is a current fact, would the figure change, if the virus mutates? Could it be that a mutated virus can re-infect formerly immune people?
But let’s postulate that the herd-immunity assumption is both correct and stable. Johnson’s herd-immunity strategy would thus require that about 40 million Brits get infected with the virus to generate the required herd-immunity. Assuming a mortality rate of 1 – 2%, this means that Johnson is cheerfully accepting 400 000 – 800 000 fatalities.
But, as I said, this scenario is based on wild assumptions. It applies only if the virus does not mutate. And it only applies, if we do not run out of intensive care (IC) beds. However, running out seems possible, perhaps even likely, considering that we have only about half of the French and just one third of the German IC capacity. Sod’s law has it that both might happen. In this case, we might easily have far in excess of 800 000 fatalities. How should we take that ‘on the chin’, Mr Johnson?
Sadly, this is not all; I have further doubts about our PM’s ideas.
The present strategy regarding diagnosis of coronavirus cases is to self-isolate once suspicious symptoms start. Even if someone is seriously ill (with high fever etc.), they are told to stay at home and sit it out. This means we will never know whether these patients had or had not suffered from a coronavirus infection. How then can we ever be sure that the 60% target of infection has been reached? And if we are uncertain about it, how can we be sure that herd-immunity will work in the way the modellers predicted?
Moreover, we now know that people who caught the virus are infective BEFORE they develop symptoms. If that is so, the strategy of self-isolation will be far less effective than predicted. And, given this fact, are we not much more likely to have a sharp peak of cases early on which would make us run out of IC capacity? When that happens, even the pessimistic death rates might turn out to be too optimistic.
It seems to me that Johnson’s herd-immunity strategy is risky to the point of being reckless. It also seems to me that there are very good reasons why other countries have not adopted it.
But what is the solution?
In my view, the solution cannot be to uncritically adopt the theories and assumptions of modellers. This is not a computer game; we are talking about human lives, many human lives!
I wish I new what the best solution is – but I don’t. I merely fear that ‘taking it on the chin’ is not a solution at all. In any case, a wise move for Johnson and his team might be to consider that foreigners might be at least as clever as they are. Subsequently they could carefully study the actions of those countries which managed to bring down their death-rates despite being attacked by the coronavirus.