Age-stratified infection fatality rate of COVID-19 in the non-elderly informed from pre-vaccination national seroprevalence studies

Abstract

The infection fatality rate (IFR) of COVID-19 among non-elderly people in the absence of vaccination or prior infection is important to estimate accurately, since 94% of the global population is younger than 70 years and 86% is younger than 60 years. In systematic searches in SeroTracker and PubMed (protocol: https://osf.io/xvupr), we identified 40 eligible national seroprevalence studies covering 38 countries with pre-vaccination seroprevalence data. For 29 countries (24 high-income, 5 others), publicly available age-stratified COVID-19 death data and age-stratified seroprevalence information were available and were included in the primary analysis. The IFRs had a median of 0.035% (interquartile range (IQR) 0.013 - 0.056%) for the 0-59 years old population, and 0.095% (IQR 0.036 - 0.125%,) for the 0-69 years old. The median IFR was 0.0003% at 0-19 years, 0.003% at 20-29 years, 0.011% at 30-39 years, 0.035% at 40-49 years, 0.129% at 50-59 years, and 0.501% at 60-69 years. Including data from another 9 countries with imputed age distribution of COVID-19 deaths yielded median IFR of 0.025-0.032% for 0-59 years and 0.063-0.082% for 0-69 years. Meta-regression analyses also suggested global IFR of 0.03% and 0.07%, respectively in these age groups. The current analysis suggests a much lower pre-vaccination IFR in non-elderly populations than previously suggested. Large differences did exist between countries and may reflect differences in comorbidities and other factors. These estimates provide a baseline from which to fathom further IFR declines with the widespread use of vaccination, prior infections, and evolution of new variants.

Avoidable Intensive Care Resource Use of Unvaccinated COVID-19 Patients: Interpretation and Policy Implications

“…35 The median IFR by age group in Pezzullo et al was a median 0.0003% at 0-19 years, 0.003% at 20-29 years, 0.011% at 30-39 years, 0.035% at 40-49 years, 0.129% at 50-59 years, and 0.501% at 60-69 years. 35 For those <70 years this is 0.33%/0.095%=3.5X lower than the case fatality rate in Canada in March, 2021; correcting for this difference between case and infection outcome rates, the infection hospitalization and ICU admission rates for those <70 years in Canada were 3.0%/3.5=0.86% and 0.7%/3.5=0.2% respectively in May, 2021 (and with Omicron variants is now likely 3-5X lower). 24 From a public health lens, serious outcomes from SARS-CoV-2 are rare in those <70 years.…”

Temporal Analysis of Vaccine Adverse Effects for Causation Inference

“…According to Ref. [11], the median IFR of COVID19 per age bin ranges between 3 × 10 −6 and 5 × 10 −3 , whereas the global IFR of COVID19 is 7 × 10 −4 for 0-69 years old (Table 1, last column). Note that the focus of Ref.…”

“…We then compared the COVID19 vaccine fatality rate per VAX_MANU with the COVID19 infection fatality rate (IFR) obtained in the latest meta-regression analysis [11]. According to Ref.…”

“…Note that the focus of Ref. [11] was on an accurate estimate of the IFR of COVID19 among non-elderly people, motivated by the fact that non-elderly people (i.e. younger than 70 years old) represent 94% of the global population.…”

“…The global vaccine fatality rate for non-elderly people is non-negligible and moreover up to two orders of magnitude larger than the IFR of COVID19 in the sample of infected patients in Ref. [11]. Actually we are measuring the probability of death by the vaccine conditional on the adverse event being reported P(death, vaccine|report) which relates to the probability of death by the vaccine P(death, vaccine) as follows:…”