What the government doesn’t yet know about the coronavirus

I understand a bit more than I did about what the prime minister, the chief medical officer Chris Whitty and the chief scientific adviser Sir Patrick Vallance are trying to achieve with their Covid-19 policy, what that policy actually is, what they actually know about the illness and – importantly – what they don’t know.

Let’s start with the most important thing they don’t know. This is the proportion of people who will get the virus but will show no symptoms.

It is a hugely important ratio, because it conditions how far the government should take measures to restrict our ability to move around and socialise.

The point is that the more people who get the illness without showing any symptoms, the fewer people will need hospitalisation – which in turn means that the fewer actions the PM would need to take to curb our precious freedoms to be with who we want, where we want and when we want.