COVID, Infection Fatality Rates

Infection fatality rate of COVID-19 inferred from seroprevalence data (WHO / Stanford, 14th October)

https://www.who.int/bulletin/online_first/BLT.20.265892.pdf

Estimate the infection fatality rate

From seroprevalence data

61 studies (74 estimates)

Eight preliminary national estimates

Seroprevalence estimates ranged from 0.02% to 53.40%

Infection fatality rates ranged from 0.00% to 1.63%

Overall IFR

Across 51 locations

Median COVID-19 infection fatality rate was 0.23%

Most locations probably have an infection fatality rate less than 0.20%

In people less than 70 years

Infection fatality rates ranged from 0.00% to 0.31%

Medians of 0.05%.

Factors in areas with low IFR

Younger population (excluding Japan)

Previous immunity from other coronaviruses

Genetic differences

Hygiene etiquette

Lower infectious load

Other unknown factors

Country IFR under 70

Argentina 0.13 0.09

Brazil 0.27 0.9

BC 0.59 0.08

Denmark 0.27 0.04

France 0.3 0.03

Italy 1.2 0.22

Netherlands 0.68 0.09

NY 0.65 0.25

S Florida 0.25 0.08

Louisiana 0.3 0.1

Bay 0.12 0.03

Georgia 0.44 0.15

Missouri 0.2 0.05

Assessing the Age Specificity
of Infection Fatality Rates for COVID-19: Systematic Review, Meta-Analysis, and Public Policy Implications
6th October

https://www.medrxiv.org/content/10.1101/2020.07.23.20160895v6.full.pdf

https://www.medrxiv.org/content/10.1101/2020.07.23.20160895v6

0.4% at age 55

1.4% at age 65

4.6% at age 75

15% at age 85

Exponential relationship between age and IFR for COVID-19

Differences in the age structure of the population explain about 90% of the geographical variation in IFR

Consequently, public health measures to mitigate infections in older adults could substantially decrease total deaths

Humoral Immune Response to SARS-CoV-2
in Iceland

https://www.nejm.org/doi/pdf/10.1056/NEJMoa2026116?articleTools=true

Measured antibodies in 1,215 diagnosed with quantitative polymerase-chain-reaction (qPCR) assay

Measured antibodies in 4222 quarantined persons who had been exposed to SARS-CoV-2

Measured antibodies in 23,452 persons not known to have been exposed

In diagnoses people

1,107 of the 1,215 who were tested (91.1%) were seropositive

Antibodies increased during 2 months after diagnosis

Remained on a plateau for the remainder of the study

In quarantined people

2.3% were seropositive

In people not known to have been exposed

0.3% tested antibody positive
Conclusions

We estimate that 0.9% of Icelanders were infected with SARS-CoV-2

Infection was fatal in 0.3% overall

New knowledge about the Iceland epidemic

We also estimate that 56% of all infections in Iceland had been diagnosed with qPCR

14% of infections had occurred in quarantined persons who had not been tested with qPCR

30% of infections had occurred in persons not known to have been exposed

Conclusions

Antiviral antibodies against SARS-CoV-2 did not decline within 4 months after diagnosis

Risk of death from infection was 0.3%

44% of persons infected with SARS-CoV-2 in Iceland were not diagnosed by qPCR.

Source