When comparing Covid-19 death rate with influenza death rate, virtually everybody (including me) has been using a 0.1% death rate for the flu.
0.1% is actually the case fatality rate for the flu, not the infection fatality rate for the flu.
“Case fatality rate” means deaths per confirmed case. “Infection fatality rate” means deaths per actual infection. Because we don’t test everybody for these infections, the infection fatality rate can only be estimated. Also, the case fatality rate will necessarily be higher than the infection fatality rate.
Technically, the case fatality rate for Covid-19 is some very-high number (because we test so few people) that means nothing right now. But the estimated infection fatality rate of Covid-19 seems to be around 0.5% to 0.8%. The infection fatality rate of influenza is estimated between 0.025% and 0.05%.
That makes infection with the novel coronavirus somewhere between 10 and 32 times deadlier than infection with an influenza virus.
And don’t forget, it’s also wildly more contagious than influenza.
