1/B

Some sources on this for those curious about how long antibodies against SARS-CoV-2 persist after infection.

I'll focus on longitudinal studies that test and re-test the same infected people.

2/B

Also, I'll focus on studies that did representative sampling of the general population.
So no sampling just hospital patients, blood donors, healthcare workers, etc.

St. Petersburg, Russia:

medrxiv.org/content/10.110…



eusp.org/en/news/over-1… Image
4/B

Jersey:

(round 2 was in late May, round 3 was in late June;
26 / 37 = ~70%)

gov.je/SiteCollection…
gov.je/SiteCollection…

gov.je/SiteCollection… Image
5/B

USA: Utah (counties such as Davis, Salt Lake, etc)

medrxiv.org/content/10.110…

"[...] during the what is now the second half of the pandemic in Utah (mid-June to mid-September) compared to the first three months of the pandemic (mid-March to mid-June)."
issuu.com/ecclesschool/d… Image
6/B

Spain:

(rounds 1: early May;
round 2: late May;
round 3: mid-June)

translation:
"[...] seronegativization [...] of 7.1% (95% CI: 5.9-8.5) between Round 1 and Round 2 and a 14.4% (95% CI: 12.7-16.3%) between Round 1 and 3 [page 1]"
portalcne.isciii.es/enecovid19/inf… Image
7/B

Additional steps are needed, such as adjusting for test specificity + sensitivity. But this list is just for review.

(ex: the study in 5/B uses a test with ~83% sensitivity, so its sample size and ~22% result is compatible with ~0% seroreversion)
medrxiv.org/content/10.110… Image
8/B

More details on the course of seroreversion from the UK Biobank study in part 6/B.

Unsurprisingly, antibody titers stay elevated post-infection for months in the vast majority of people.

@CovidSerology

gov.uk/government/pub…

ukbiobank.ac.uk/media/x0nd5sul… Image

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More from @AtomsksSanakan

5 Feb
1/J

Wanted to address some issues in the thread below from another immunologist.

Should be a nice change-of-pace from dealing with obvious nonsense from disingenuous denialists.



Image
2/J

Serology isn't missing many asymptomatic + pauci-symptomatic infections, once one adjusts for sensitivity based on calibration (long-term sensitivity is better for anti-spike vs. anti-nucleocapsid)



jvi.asm.org/content/95/3/e…

immunology.sciencemag.org/content/5/54/e… Image
3/J

You're not going to get places with >55% seroprevalence with high specificity tests, if you're missing a lot of infections.



66% - 70%: medrxiv.org/content/10.110…
74%: icddrb.org/news-and-event…

academic.oup.com/ofid/advance-a…

ins.gov.co/BibliotecaDigi… Image
Read 9 tweets
23 Dec 20
1/X

Those behind the Great Barrington Declaration mention herd immunity as a way to address COVID-19.

So I'll discuss it. After all, noting herd immunity (in response to vaccine deniers) is 1 main reason I started on Twitter.



gbdeclaration.org Image
2/X

Suppose u want to know how many people would die from COVID-19 under *baseline conditions*.

So basically: treat COVID-19 like another typical disease, with business-as-usual and acting the same as this time last year without the pandemic.

3/X

Re: "how many people would die from COVID-19 under *baseline conditions*"

One can figure that out using:
- the number of people who would get infected
- how many of those infected people die of COVID-19

A separate thread on the latter point:
Read 43 tweets
22 Dec 20
1/

Many COVID-19 contrarians, including those behind the Great Barrington Declaration, *still* cite John Ioannidis' inaccurate estimate of SARS-CoV-2's fatality rate.

So let's go over how atrocious Ioannidis' paper is.



web.archive.org/web/2020111809… Image
2/

Background:

When a virus infects u, your body increases production of proteins known as antibodies, which are usually specific to that virus.

So measuring antibodies lets u estimate who was infected, and from that the infection fatality rate (IFR).

institutefordiseasemodeling.github.io/nCoV-public/an… Image
3/

Ioannidis uses antibody (a.k.a. seroprevalence) studies to estimate the number of people infected with the virus SARS-CoV-2. He then calculates IFR by dividing the number of COVID-19 deaths by the number of infected people.

Ioannidis does this badly:
medrxiv.org/content/10.110… Image
Read 45 tweets
8 Dec 20
1/P

Peter C Gøtzsche (@PGtzsche1) wrote the article below

He argues that COVID-19 isn't very lethal, + then draws some political conclusions.

The article is poor.

"Is the infection fatality rate for COVID-19 worse than that for influenza?"
bmj.com/content/371/bm…
2/P

Gøtzsche's basic idea is:
The proportion of SARS-CoV-2-infected people who die of the disease COVID-19 is comparable to that of flu; i.e. the infection fatality rate (IFR) for COVID-19 is not an order of magnitude larger than that of the flu.

So:
bmj.com/content/371/bm…
3/P

Gøtzsche is wrong. Study after study shows that the fatality rate for SARS-CoV-2 is about an order of magnitude larger than that of influenza; COVID-19 is way more dangerous than the flu.

So where does Gøtzsche go wrong?



link.springer.com/article/10.100…
Read 16 tweets
4 Dec 20
The USA's SeroHub is out. It purports to cover SARS-CoV-2 seroprevalence studies in the USA.

It includes the quite bad, non-peer-reviewed Santa Clara study. So I thought I'd include some other USA studies SeroHub now leaves out.



covid19serohub.nih.gov
Re: "some other USA studies SeroHub now leaves out"

Baton Rouge, Louisiana
medrxiv.org/content/10.110…

Ohio
arxiv.org/abs/2011.09033
coronavirus.ohio.gov/static/dashboa…

Washoe County, Nevada
washoecounty.us/outreach/2020/…

4 Utah counties
medrxiv.org/content/10.110…
Re: "some other USA studies SeroHub now leaves out"

Maricopa County, Arizona
maricopa.gov/CivicAlerts.as…
maricopa.gov/5607/COVID-19-…

Orange County, California
medrxiv.org/content/10.110…

Riverside County, California
rivcoph.org/Portals/0/Docu…

Connecticut
amjmed.com/article/S0002-…
Read 5 tweets
25 Nov 20
It's almost 2021.
And I don't forget, even years later. 🙂



For analyzing global warming trends:
ysbl.york.ac.uk/~cowtan/applet…
psl.noaa.gov/cgi-bin/data/t…
climexp.knmi.nl/start.cgi

Judith Curry (@curryja), in 2016:
judithcurry.com/2016/03/06/end…
Someone will have a lot to answer for in 2021...

"I do receive some funding from the fossil fuel industry"
scientificamerican.com/article/climat…

"Politically I am independent, with libertarian leanings."
culturalcognition.net/blog/2014/8/19…



judithcurry.com/2011/10/27/can…
Read 4 tweets

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