1/

There's been a resurgence in the myth that SARS-CoV-2, the virus that causes COVID-19, kills ~0.26% of the people it infects in the US.

In other words:
The infection fatality rate (IFR) is ~0.26%.

https://physiciansforinformedconsent.org/COVID-19/ 
https://www.medrxiv.org/content/10.1101/2020.05.13.20101253v3.full.pdf https://twitter.com/JamesTodaroMD/status/1281217211269623809

3/

The USA's CDC formerly gave an IFR estimate of ~0.26%, without ever citing evidence for it:
https://www.npr.org/sections/health-shots/2020/05/22/860981956/scientists-say-new-lower-cdc-estimates-for-severity-of-covid-19-are-optimistic
https://www.usatoday.com/story/news/factcheck/2020/06/05/fact-check-cdc-estimates-covid-19-death-rate-0-26/5269331002/
https://www.nationalreview.com/corner/cdc-updates-covid-19-fatality-rate-best-estimate/
https://twitter.com/CT_Bergstrom/status/1279612720489234434

They recently changed to 0.65%, and cited evidence for that:
https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html#table-1

4/

The CDC's cited source is the paper from part 2/.

But that paper states it likely *under-estimates* IFR:

"[when only analysing those serosurveys that had a low risk of bias] the inferred IFR rises substantially to 0.76% (0.37-1.15%)"
https://www.medrxiv.org/content/10.1101/2020.05.03.20089854v4.full.pdf

5/

So I'll start with updates of values from a previous thread:

New York City
0.5% - 1.5% (at different times in the pandemic)
https://web.archive.org/web/20200708120828/https://www.medrxiv.org/content/10.1101/2020.06.27.20141689v1.full.pdf
https://web.archive.org/web/20200710064618/https://www.medrxiv.org/content/10.1101/2020.06.22.20137208v1.full.pdf

New York state
0.8%
0.6%

Orleans and Jefferson Parish, Louisiana
1.6% https://twitter.com/AtomsksSanakan/status/1276603678397476867

6/

Updated:

Indiana
April : 0.6%
June : 1.7%
https://www.cdc.gov/mmwr/volumes/69/wr/mm6929e1.htm
https://news.iu.edu/stories/2020/06/iupui/releases/17-fairbanks-isdh-second-phase-covid-19-testing-indiana-research.html

Chelsea, Massachusetts:
0.2% - 1.0% [mode: 0.3% - 0.5%]
https://www.tandfonline.com/doi/full/10.1080/13669877.2020.1778771 https://twitter.com/AtomsksSanakan/status/1276605278277025796

7/

Updated:

USA
0.07% - 1.4%
1.0%
0.9%
https://www.medrxiv.org/content/10.1101/2020.06.21.20136580v1.full.pdf

Arizona
0.7%

Florida
0.3% https://twitter.com/AtomsksSanakan/status/1276607142280249344

8/

Santa Clara County, California
0.2%
0.2% - 1.0% [mode: 0.3% - 0.5%]
https://www.medrxiv.org/content/10.1101/2020.05.03.20089854v4.full.pdf

Washoe County, Nevada
0.8% {re-calculated: 0.9%}
https://www.washoecounty.us/outreach/2020/07/2020-07-08-jic-update-0708.php

DeKalb County and Fulton County, Georgia
0.5%
https://www.cdc.gov/mmwr/volumes/69/wr/mm6929e2.htm https://twitter.com/AtomsksSanakan/status/1276778791877124098

9/

Davis, Salt Lake, Summit and Utah counties, Utah
0.3% {re-calculated for right-censoring: 0.6%}
https://healthcare.utah.edu/publicaffairs/news/2020/07/utah-hero-project-phase-1.php

Blaine County, Idaho
0.1% (dubious)
https://web.archive.org/web/20200721223820/https://www.medrxiv.org/content/10.1101/2020.07.19.20157198v1.full.pdf

Rhode Island
3.6% (dubious) https://twitter.com/AtomsksSanakan/status/1276601838981255174

10/

For Los Angeles County, California:
"One study explicitly warned against using its data to obtain an IFR"
https://www.medrxiv.org/content/10.1101/2020.05.03.20089854v4.full.pdf
[ https://jamanetwork.com/journals/jama/fullarticle/2766367]

And some context of estimating IFR from seroprevalence (antibody-based) studies:
https://academic.oup.com/jid/article/doi/10.1093/infdis/jiaa429/5872489

11/

Part 4/ stated that excess mortality shows COVID-19 deaths are under-estimated, and thus IFR is under-estimated.

If so, then this makes the IFRs on this thread ~25% larger, on average.

Further context on this below:

https://twitter.com/AtomsksSanakan/status/1286027881492209664