"Several previous evaluations (Ioannidis, 2021a; Levin et al., 2020; O’Driscoll et al., 2021; Brazeau et al., 2020) have already synthesized information on age-stratified estimates of IFR. Most of those used data from early published studies, and these tended to have information from mostly hard hit countries, thus potentially with inflated IFR estimates. Moreover, several analytical and design choices for these reviews and data syntheses can be contested (Ioannidis, 2021b) and many more potentially informative seroprevalence studies have been published since then."