Yes, a week may be a long time in politics, comments Sir Bernard Jenkin MP, but the expression wasn’t conceived for situations like Covid-19

For those of you reading, this article is probably landing on your desk at a rather unusual time. From my position in Westminster, the world today seems so far removed from only three months ago, when the United Kingdom was facing a General Election, whether we would leave the European Union was still the paramount concern, and the world was slowly turning towards the intensifying presidential race in the United States. It has been said that a week is a long time in politics, but I don’t think it was meant to cover situations like this.

At times like this, the role of government as a colossal risk management organisation comes into the fore. The Fifth Risk, a book by Michael Lewis, is dedicated entirely to this concept: taking the reader on a tour through obscure departments of the US government to explain how the state attempts to plan for events as unlikely as nuclear catastrophe or unexpected wars. In our current time of epidemics, such planning must seem more than welcome.

In the UK, we had our own unexpected brush with normally unloved modellers in mid-March, when the Imperial College London published an epidemiology paper that had just become a key factor in the public health policy of this country and the United States. The paper outlined two key strategies in the fight against Covid-19: suppression and mitigation. The former, which was seen earlier on in South Korea, Hubei province and, eventually, Italy, involved a complete lockdown of everyday life. People would not be allowed to leave their homes except for essential journeys such as buying food. All those who could had to work from home. Schools and universities would be closed, and social distancing ruthlessly enforced. The modelling showed that this would have a transformative effect on the number of new Covid-19 cases: reducing them down to almost zero in a few months. The catch, however, was that these measures would only be effective as long as they were in place. Whenever we left our cages, as it were, the virus would come out with us.

The second strategy, to mitigate the spread of the virus, did not aim to completely smother its spread. Instead, it attempts to manage the rate of infection so as not to overwhelm the healthcare system. Doing this, it therefore will lead to a constant, but relatively low rate of new cases and thereby attempt to slowly allow the entire population to catch the virus. This has the benefit of eventually introducing what is called ‘herd immunity’, in which a critical mass of immune people will simultaneously be incapable of being affected by the disease, nor able to infect others. This is the principle behind mass vaccination: not only is it almost impossible for a disease to thrive in a person who has had the vaccine, but it is also extremely hard for the disease to find unvaccinated victims when it can only do so by going through someone who has already been treated.

The problem with this strategy, as the paper bore out, was in the sheer scale of the infection. Almost no healthcare system in the world has the extra surge capacity needed for an epidemic of this scale. After all, this would entail thousands of spare beds lying empty, warehouses of unused ventilators and tens of thousands of extra staff trained in using them, all uselessly until the new virus reared its ugly head. And as the maths showed, plugging in new data from Italy and China, even in the strongest possible form of the mitigation strategy, the number of sick people would rapidly overwhelm the UK’s supply of hospital beds and critical care equipment. Under previous assumptions on the rate of hospitalisation and the proportion of those who would need intensive care, our National Health Service might have had a chance. But after knowing the real potential of Covid-19, it would have been a matter of weeks (if that) until hospitals were completely overwhelmed. The alternative was to keep rates of infection at such low rates that our healthcare system could keep up, but the cost would be too few cases to build a serious level of population immunity. The inevitable conclusion was that, until the advent of either a vaccine, new treatment or a surge in healthcare capacity, suppression was all that was left.

We should all be grateful not only for the transparency of such thinking, but for its existence at all. If the field of epidemiology didn’t exist, or if the government weren’t plugged directly into it specifically for times such as these, I shudder to think what might have happened across the globe. Only time will tell us whether suppression is a viable long-term strategy, or whether new discoveries change the assumptions upon which it is built. Until then, the radically different world we now occupy beckons.