Infection fatality rate of COVID-19 inferred from seroprevalence data

Abstract

Objective To estimate the infection fatality rate of coronavirus disease 2019 (COVID-19) from seroprevalence data. Methods I searched PubMed and preprint servers for COVID-19 seroprevalence studies with a sample size ≥ 500 as of 9 September 2020. I also retrieved additional results of national studies from preliminary press releases and reports. I assessed the studies for design features and seroprevalence estimates. I estimated the infection fatality rate for each study by dividing the cumulative number of COVID-19 deaths by the number of people estimated to be infected in each region. I corrected for the number of immunoglobin (Ig) types tested (IgG, IgM, IgA). Findings I included 61 studies (74 estimates) and eight preliminary national estimates. Seroprevalence estimates ranged from 0.02% to 53.40%. Infection fatality rates ranged from 0.00% to 1.63%, corrected values from 0.00% to 1.54%. Across 51 locations, the median COVID-19 infection fatality rate was 0.27% (corrected 0.23%): the rate was 0.09% in locations with COVID-19 population mortality rates less than the global average (< 118 deaths/million), 0.20% in locations with 118–500 COVID-19 deaths/million people and 0.57% in locations with > 500 COVID-19 deaths/million people. In people younger than 70 years, infection fatality rates ranged from 0.00% to 0.31% with crude and corrected medians of 0.05%. Conclusion The infection fatality rate of COVID-19 can vary substantially across different locations and this may reflect differences in population age structure and case-mix of infected and deceased patients and other factors. The inferred infection fatality rates tended to be much lower than estimates made earlier in the pandemic.

COVID-19: Rethinking the Lockdown Groupthink

“…Based on seroprevalence data as of September 9, 2020, including 82 estimates from across 51 locations in the world, Ioannidis found that the median corrected IFR was 0.23% (range 0.00-1.54%) (26). Among those <70 years old the median crude and corrected IFR was 0.05% (range 0.00-0.31%).…”

“…He estimated that for those <45 years old the IFR was almost 0%, 45-70 years old approximately 0.05-0.30%, and ≥70 years old ≥ 1%, rising to up to 25% for some frail older people in nursing homes (27). He estimated that at that point there were likely 150-300 million infections that had occurred in the world, not the reported 13 million, most being asymptomatic or mildly symptomatic (26,27). The WHO recently estimated that about 10% of the global population may have been already infected, which, with a world population of 7.8 billion, and 1.16 million deaths, would make a rough approximation of IFR as 0.15% (28).…”

“…Moreover, at least 10% of COVID-19 patients never seroconvert, and many more may only develop a mucosal IgA response (37,38), or only a T-cell response (which may be the case in up to 50% of mild infections) (39,40). Finally, most data come from unusual epicenters where infection finds its way into killing predominantly older citizens in nursing homes and hospitals (26), and where "[in Italy, Spain, France] an underfunded, understaffed, overstretched and increasingly privatized and fractured healthcare system contribute to higher mortality rates. .…”

“…[Lombardy] has long been an experimental site for healthcare privatization (page 474-475)" (10). With "precise non-pharmacological measures that selectively try to protect high-risk vulnerable populations and settings, the IFR may be brought even lower (page 10)" (26).…”

Evaluation of the factors affecting the formation of humoral immunity to the SARS-COV-2 coronavirus in medical students and doctors of the Republic of Crimea during active phase of the COVID-19 pandemia

“…Масштабные исследования по данной тематике были проведены в Китае, США, Испании, Швейцарии и Швеции [5][6][7]. Согласно опубликованным данным, можно сделать выводы о довольно низких уровнях серопревалентности к коронавирусу SARS-CoV-2 среди населения даже наиболее пострадавших регионов.…”