Here's another recent meta-study (preprint) on the same topic: Assessing the Age Specificity of Infection Fatality Rates for COVID-19: Systematic Review, Meta-Analysis, and Public Policy Implications https://www.medrxiv.org/content/10.1101/2020.07.23.20160895v...
Abstract: This paper assesses the age specificity of the infection fatality rate (IFR) for COVID-19 using results from 29 seroprevalence studies as well as five countries that have engaged in comprehensive tracing of COVID-19 cases. The estimated IFR is close to zero for children and younger adults but rises exponentially with age, reaching 0.4% at age 55, 1.4% at age 65, 4.6% at age 75, and 15% at age 85. We find that differences in the age structure of the population and the age-specific prevalence of COVID-19 explain nearly 90% of the geographical variation in population IFR. Consequently, protecting vulnerable age groups could substantially reduce the incidence of mortality.
I think those results are in the same ballpark as what Ioannidis calculates. This isn't good news, really, not for middle-aged-adults anyway.
Abstract: This paper assesses the age specificity of the infection fatality rate (IFR) for COVID-19 using results from 29 seroprevalence studies as well as five countries that have engaged in comprehensive tracing of COVID-19 cases. The estimated IFR is close to zero for children and younger adults but rises exponentially with age, reaching 0.4% at age 55, 1.4% at age 65, 4.6% at age 75, and 15% at age 85. We find that differences in the age structure of the population and the age-specific prevalence of COVID-19 explain nearly 90% of the geographical variation in population IFR. Consequently, protecting vulnerable age groups could substantially reduce the incidence of mortality.
I think those results are in the same ballpark as what Ioannidis calculates. This isn't good news, really, not for middle-aged-adults anyway.
IFR(age) = 0.1 x 10^((age-82)/20)