When lockdown was first imposed, there was little science to base it on. The virus was assumed to be growing at an exponential rate, with each infected person passing it on to about four others. The controversial assumption: only mandatory lockdown could stop this. Graphs were drawn, showing the infection rate barely dented by voluntary measures (like handwashing, keeping socially distanced etc.) but lockdown making things safe instantly. Imperial College’s cliff-edge graph had huge traction (the below is a BBC reproduction) and made an open-and-shut case for lockdown.
The above assumptions were the basis of a recent Sunday Times investigation entitled ‘UK’s lockdown dithering led to worst death toll in Europe.’
This was largely based on guesswork but there was – at the time – no real alternative. There is now. We now know enough about the virus to look at hospital figures and work backwards, drawing a chart of its likely infection rate. These tend to draw a different shape: the infection rate rising, hitting a peak, then falling fast. But what makes it fall? Lockdown – or something else? Norway found that the virus had peaked before lockdown and was in fast decline. This led the Norwegian public health chief to say that they could have controlled it without locking down – relying, instead, on the social distancing going on at the time. This is relevant, the Norwegians say, because if there is a second wave we need to be brutally honest about what works and what does not.
Now, a version of this study for England and Wales has been done by Simon Wood, a professor at Bristol University. The study is here (pdf`) and main graph is below.
It shows that infections peaked about five days before lockdown and were in fast decline by the time it was introduced.