Straight to the point

Studies on Covid-19 Lethality

Published: May 12, 2020; Last updated: June 12, 2020
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1) Covid-19 infection fatality rates (IFR) based on antibody studies

Immunological research indicates that serological antibody studies, which measure antibodies in the blood (IgG and IgM) and typically found population-based IFR values between 0.1% and 0.5%, may detect at most 20% of infections, as most people neutralize the coronavirus with their mucosal (IgA) or cellular (T cells) immune system while developing only mild symptoms or no symptoms. This means serological IFR values may drop by a factor of five to values at or below 0.1%.

Country	Published	Population	IFR (%)	Source
Global	May 23	Global	≤0.10	Report / Study

Population-based antibody seroprevalence studies:

Country	Published	Population	IFR (%)	Source
Global	June 8	23 studies	0.25¹	Study
Germany	May 4	Heinsberg Cluster	<0.36²	Study
Iran	May 1	Guilan province	<0.12	Study
USA	April 30	Santa Clara County	0.17	Study
Denmark	April 28	Blood donors (<70y)	0.08	Study
USA	April 24	Miami-Dade County	<0.18	Report
USA	April 21	Los Angeles County	<0.20	Study

1) Median value; 2) The adjusted IFR is 0.27% (page 9). Note: Some of these studies are preprints.

2) Covid-19 infection fatality rates based on controlled PCR studies

Controlled PCR studies in population subgroups.

Country	Date	Population	IFR (%)	Source
France	May 21	Health workers	0.05	Study
USA	May 10	MLB employees	0.00	Report
France	May 10	Aircraft carrier	0.00	Report
USA	May 10	Aircraft carrier	0.09	Report
USA	May 1	Tennessee prison	0.00	Report
Italy	April 28	Health workers	0.30¹	Study
USA	April 17	Boston homeless	0.00	Report
USA	April 17	Boston blood donors	0.00	Report
Greece	April 16	Repatriations	0.00	Study
USA	April 13	NYC pregnant women	0.00	Study
Ship	March 17	Diamond Princess	0.13²	Study

1) See table below; 2) Age-adjusted IFR based on US population.

3) Covid-19 infection fatality rates based on models

Covid-19 IFR based on epidemiological models or predictions. These values are often somewhat higher than the actual values based on serological antibody studies (see above).

Country	Published	Population	IFR (%)	Source
USA	May 20	CDC estimate	0.26¹	Study
France	May 13	France	0.70	Study
Switzerland	May 11	Switzerland	0.40	Study
UK	May 7	UK	0.08²	Study
France	May 7	France	0.80³	Study
Global	May 6	Metastudy	0.64	Study
Global	May 5	Global	0.17	Study
India	May 3	India	0.41	Study
Italy USA	April 20	Lombardia New York City	>0.84 >0.50	Study
China	March 30	Mainland China	0.66	Study
China	March 13	Wuhan city	0.12	Study
China	March 9	Mainland China	0.50	Study

1) 0.4% symptomatic CFR and 35% asymptomatic cases; 2) Based on 29% prevalence and 50,000 deaths; 3) The IFR is 0.50 excluding nursing homes.

4) Additional antibody and PCR studies

These studies determine the prevalence of recent or current Covid-19 infections in a population or region. In most cases, they find that Covid-19 is much more widespread than previously assumed, with most people showing no or only mild symptoms.

Country	Published	Population	Prev.	Factor	Source
Russia	June 10	Russia	14%	40x	Report
USA	May 15	Boston	12.5%	8x	Report
Czech Rep.	May 15	South Bohemia	5%	10x	Report
USA	May 13	Indiana	2.8%	11x	Report
Spain	May 13	Spain Madrid	5% 11.3%	10x	Study
UK	May 8	UK	29%	200x	Study
Switzerland	May 6	Geneva	9.7%	10x	Study
Global	May 5	< 65 years old			Study
Japan	May 5	Kobe City	2.7%	396x	Study
USA	May 2	New York State New York City	12.3% 19.9%	8x 10x	Report
Spain	May 2	Health workers	11.2%		Study
Netherlands	April 29	Blood donors	2.7%		Study
France	April 23	Northern France	3%		Study
USA	April 19	Chelsea MA	32%	16x	Report
Iceland	April 14	Iceland (PCR)	0.8%		Study

5) Median age of Covid-19 deaths per country

Half of all deaths were below, half were above the median age.

Country	Median age	Source
Austria	80+ years	EMS
England	80+ years	NHS
France	84 years	SPF
Germany	82 years	RKI
Italy	81 years	ISS
Spain	~82 years	MDS
Sweden	86 years	FOHM
Switzerland	84 years	BAG
USA	~80 years	CDC

7) Hospitalization rate

Initial estimates based on Chinese data assumed a very high 20% hospitalization rate, which led to the strategy of ‘flattening the curve’ to avoid overburdening hospitals. However, population-based antibody studies (see above) have since shown that actual hospitalization rates are close to 1%, which is within the range of hospitalization rates for influenza (1 to 2%).

The US CDC found that Covid-19 hospitalization rates for people aged 65 and over are “within ranges of influenza hospitalization rates”, with rates slightly higher for people aged 18 to 64 and “much lower” (compared to influenza) for people under 18.

In local hotspots like New York City, the overall hospitalization rate based on antibody studies is about 2.5% (19.9% or 1.7 million people with antibodies and 43,000 hospitalizations by May 2).

The much lower than expected hospitalization rate may explain why most Covid-19 ‘field hospitals’ even in hard-hit countries like the US, the UK and China remained largely empty.

8) Percentage of Covid-19 deaths in care homes per country

In many countries, deaths in care homes account for 30 to 60% of all additional deaths. In Canada and some US states, care homes account for up to 80% of all “Covid19-related” deaths.

Source: Mortality associated with COVID-19 outbreaks in care homes (LTC Covid, May 3, 2020)

Source: The Covid-19 Nursing Home Crisis by The Numbers (Freopp, May 12, 2020)

9) Overall mortality

In countries like the US, the UK, and even Sweden (without a lockdown), overall mortality since the beginning of the year is in the range of a strong influenza season; in countries like Germany, Austria and Switzerland, overall mortality is in the range of a mild influenza season.

Sources: US, UK-1, UK-2, Sweden, Switzerland, Germany

10) Development of the epidemic

Even in countries without a lockdown, the epidemic reached its peak within a few weeks of the outbreak. However, many media showed cumulative deaths per day of report (left) instead of daily deaths per day of death (right), falsely implying an ever escalating situation.