evidence: How fatal is covid-19 compared with seasonal influenza? The devil is in the detail. Accurate assessment of the chance of death following exposure to covid-19 is important, since this statistic has been used by governments to direct lockdowns in an effort to mitigate these deaths. In correspondence to the BMJ, professors Baker and Wilson, both proponents of New Zealand’s lockdown, have criticised our assertion that the infection fatality proportion (IFP) of covid-19 is similar to seasonal influenza.[1] They claim that the IFP for influenza is 0.039%, about six times lower than the IFP for covid-19 we cited, a corrected median value of 0.23%.[2] [...] So, what is a reasonable IFP for covid-19? The overall corrected median IFP from 61 studies in a meta-analysis is 0.23%.[2] This agrees with a population serosurvey in Indiana.[20] These studies consider only seropositivity as an indicator of cumulative exposure to the virus. They have also assumed cause of death figures are accurate. So, once these factors have been considered, we believe that our comparison with seasonal influenza is not misleading. Since models that have incorporated higher IFPs have led to economically crippling lockdowns,[21] we believe scrutiny of these comparisons are vital and a reappraisal of the covid-19 IFP is overdue.