Comment on Neil Ferguson parliamentary evidence for Science Media Centre

Description

The epidemic was doubling every three to four days before lockdown interventions were introduced. So had we introduced lockdown measures a week earlier, we would have reduced the final death toll by at least a half.

Whilst I think the measures, given what we knew about this virus then, in terms of its transmission and its lethality, were warranted, I’m second guessing at this point, certainly had we introduced them earlier we would have seen many fewer deaths. - Ferguson

Comment:

I think it is too early to talk about the final death toll, particularly if we include the substantial non-covid loss of life that has been and will be caused by the effects of lockdown. If the science behind the lockdown is correct, then the epidemic and the counter measures are not over.

The figure of `at least a half’ appears to be based on exponential growth in infections up to lockdown. But if you take the Ferguson group’s published fatal disease duration distribution and the data on deaths with covid-19 by day (from ONS), then these are also consistent with fatal infections being in decline several days before lockdown, rather than exponentially increasing. Data from other countries also suggests that measures short of full lockdown can halt epidemic growth. These facts suggest a reduced role for full lockdown in saving life from covid-19, since it appears that pre-lockdown measures may also have played a substantial role in reducing infection rates. So the basis for the `at least a half’ figure does not seem robust, even considering only the immediate deaths with covid-19. If you consider the premature deaths caused by lockdown as well, we will have to wait a long time to know if it saved life.

The main difficulty pre-lockdown was that decisions were almost completely reliant on modelling, without the solid data on the epidemic size that randomized community testing would have provided.