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Reinfection Rates among Patients who Previously Tested Positive for COVID-19: a Retrospective Cohort Study
Oxford ^ | 15 Mar 2021 | Megan M Sheehan 1, Anita J Reddy 2, Michael B Rothberg 3

Posted on 09/08/2021 11:26:14 PM PDT by blueplum

This retrospective cohort study of 1 health system included 150 325 patients tested for COVID-19 infection via polymerase chain reaction from 12 March 2020 to 30 August 2020. Testing performed up to 24 February 2021 in these patients was included. The main outcome was reinfection, defined as infection ≥90 days after initial testing. Secondary outcomes were symptomatic infection and protection of prior infection against reinfection.

Results Of 150 325 patients, 8845 (5.9%) tested positive and 141 480 (94.1%) tested negative before 30 August. A total of 1278 (14.4%) positive patients were retested after 90 days, and 62 had possible reinfection. Of those, 31 (50%) were symptomatic. Of those with initial negative testing, 5449 (3.9%) were subsequently positive and 3191 of those (58.5%) were symptomatic. Protection offered from prior infection was 81.8% (95% confidence interval [CI], 76.6–85.8) and against symptomatic infection was 84.5% (95% CI, 77.9–89.1). This protection increased over time.

(Excerpt) Read more at academic.oup.com ...


TOPICS: Chit/Chat; Health/Medicine; Science
KEYWORDS: ccpvirus; covid; covidstudies; naturalimmunity
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To note: this study was completed prior to the appearance of Delta variant, so it's anybody's guess if the 81.8%/84.5% avg, is valid for Delta exposure, but at least it's numbers that can be compared to acquired immunity numbers.
1 posted on 09/08/2021 11:26:14 PM PDT by blueplum
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To: blueplum

My understanding is that the delta variant is is not controlled as effectively as the alpha. I believe that this is factual.


2 posted on 09/08/2021 11:31:44 PM PDT by jrestrepo (Now I am an insurgent. Starve the beast (any way possible) )
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To: blueplum

Reinfection or long haulers?


3 posted on 09/08/2021 11:38:08 PM PDT by DannyTN
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To: blueplum

It BS. There is a much better Israel study released mmaybe 3 weeks ago, shows 19 out of 16,000 no reinfection after prior confirmed infection, 13x higher than vaxed.

https://hotair.com/allahpundit/2021/08/26/large-israeli-study-natural-immunity-provides-13-times-more-protection-against-delta-than-pfizers-vaccine-does-n411863


4 posted on 09/08/2021 11:41:26 PM PDT by Basket_of_Deplorables (Convention Of States is our only hope now! Desantis 2024!!!)
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To: Basket_of_Deplorables

19 out of 16,000 is 0.1%. so 99.9% don’t get it twice. As expected. Just like SARS-1-CoV.

There is almost zero chance of getting it twice.


5 posted on 09/08/2021 11:43:24 PM PDT by Basket_of_Deplorables (Convention Of States is our only hope now! Desantis 2024!!!)
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To: All

We will never get decent test data for infections and re-infections. The reason for this is the testing all involves turning people loose to walk around in society and having no idea if they ever encounter the virus to become infected.

If someone has been infected before, chances are they’re paranoid about it and will be the ultimate in social distancing and mask-wearing. Of course they don’t get re-infected. They make damn sure they’re never around anything that might infect them.

A proper test would have the test subject inhale virus and see if this supposed acquired immunity can stop it. That test will never be done, it will never be approved, and probably no test subject would be willing to do it. The exact same reality is true of vax versus non vax. You have no idea if the test subject ever encounters the virus.


6 posted on 09/08/2021 11:51:42 PM PDT by Owen
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To: blueplum
polymerase chain reaction == PCR

A test that even the CDC admits cannot tell the difference between the common every-day flu and COVID-19.

A test that if the cycles of said test, according to its inventor, is performed with 30+ cycles, throws a false-positive rate of 80%+. And that 30+ cycles rate, is what I believe most hospitals are using.

So, in conclusion, if your study is based on the failed PCR test, it is worthless.
7 posted on 09/08/2021 11:58:50 PM PDT by SoConPubbie (Mitt and Obama: They're the same poison, just a different potency)
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To: blueplum

This kind of study is very sensitive to the accuracy of the testing/diagnosis. And our current testing is crap. The very fact that flu and bad colds “disappeared” during the pandemic, tells us the testing is crap.

The disappeared diseases simply got lumped into the C19 stats via false test positives or reports of symptoms, because the criteria for a positive diagnosis is not completely specific to SARS-CoV-2 of any strain.

We don’t know what we think we know. About most things.


8 posted on 09/09/2021 12:07:12 AM PDT by JustaTech (A mind is a terrible thing)
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To: SoConPubbie

I think symptomatic infection is the better baseline. but that baseline and the total study #, can be used to guestimate the # asymptomatics pretty well without a PCR test, using the rate of asymptomatics in the genpop as a reference.

For instance, we know that only about 20% of the US pop acquired wild immunity. So we can guestimate that 15-20% roughly of those wildings, were reinfected.


9 posted on 09/09/2021 12:14:33 AM PDT by blueplum ("...this moment is your moment: it belongs to you... " President Donald J. Trump, Jan 20, 2017) )
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To: JustaTech

I’d go with your ‘colds disappeared’ theory IF we had open borders and gads of tourists carrying germs coming in. But we shut tourism. Especially from China where most flu seems to originate. So I’d say ‘colds disappeared’ because we stopped carriers from coming in.


10 posted on 09/09/2021 12:19:44 AM PDT by blueplum ("...this moment is your moment: it belongs to you... " President Donald J. Trump, Jan 20, 2017) )
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>> To note: this study was completed prior to the appearance of Delta variant,

>> “Testing performed up to 24 February 2021”

Natural immunity.


11 posted on 09/09/2021 12:38:06 AM PDT by Gene Eric (Don't be a statist!)
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To: blueplum
For instance, we know that only about 20% of the US pop acquired wild immunity. So we can guestimate that 15-20% roughly of those wildings, were reinfected.

We "know" how?

And lets play devil's advocate here and pretend your figures are accurate, it still does not absolve the article from being pure, unadulterated propanda.

Any study using the PCR as its basis is blatantly unreliable. It is only good for fire starting using the paper it is printed on.
12 posted on 09/09/2021 12:40:42 AM PDT by SoConPubbie (Mitt and Obama: They're the same poison, just a different potency)
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To: blueplum

When Democrats import third worlders from central and south America or Africa or Afghanistan they refuse to test them for covid. They are trying to turn the USA into a third world country. I read an article over at Breitbart about that, “…Fauci Silent as Measles Breaks Out at Afghan Refugee Camp”, so give that a look. Re-introducing diseases we’ve eliminated isn’t a good idea. Now we have measles AGAIN in areas Afghani’s are being settled (red states).


13 posted on 09/09/2021 1:00:00 AM PDT by ProfessorGoldiloxx
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To: jrestrepo

There is no ‘delta variant’. Nobody is dying from flu any more either, covid ‘cured’ it.


14 posted on 09/09/2021 1:01:17 AM PDT by ProfessorGoldiloxx
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To: Owen

And the ‘test’ is basically a coin flip. You ave virtually identical odds of it being correct.


15 posted on 09/09/2021 1:02:17 AM PDT by ProfessorGoldiloxx
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To: blueplum

Agreed, and in addition... A lot of people with “symptoms” (colds) were tested, turned up negative, and then, given the environment, who the heck who tests negative is going to go to a clinic or ER, where Covid exposure is likely high, for a cold?

Remember those positivity rates? A lot more people who had “something” had something else, than those that had Covid.

Also, Covid is very infection for 2-3 days (or more?) when one feels only slightly ill, if at all, and carriers can be spreading all that time. With flu, that window is very short — most flu spreaders are the people who feel they have to tough it out: Most flu victims go home to bed. In the “Covid environment”, most of those who felt bad DID do the responsible thing and go home. That slows flu tremendously. Observation of school districts “hot” with flu in the past bears this out. When those districts temporarily shut down, as they usually do, flu cases drop like a rock. Last year with Covid, in-school classes were often already shut down.

Finally, mitigation in general is far more effective for flu than Covid.

Sometimes I think these people (the majority of FReepers?) who don’t understand the differences between flu and Covid would not understand the differences between dogs and cats if they were familiar with dogs and then met up with a cat for the 1st time. (Eye roll)


16 posted on 09/09/2021 1:10:37 AM PDT by Paul R. (You know your pullets are dumb if they don't recognize a half Whopper as food!)
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To: blueplum

Whups, that was supposed to be:

Also, Covid is very infectious for 2-3 days...


17 posted on 09/09/2021 1:15:17 AM PDT by Paul R. (You know your pullets are dumb if they don't recognize a half Whopper as food!)
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To: SoConPubbie

ok, sorry, the ‘we’ should be studies say. Fair enough challenge.

studies referenced here:

“Even in local areas that have experienced some of the greatest rises in excess deaths during the covid-19 pandemic, serological surveys since the peak indicate that at most only around a fifth of people have antibodies to SARS-CoV-2: 23% in New York, 18% in London, 11% in Madrid.123
https://www.bmj.com/content/370/bmj.m3563

devils advocate is cool and very FR :)

Let’s accept that the PCR test is unreliable
What about antigen and serum (blood) tests. Do we disallow them also? If we say even one may be valid, the asymptomatic can still be confirmed and the symptomatic reinfected # remains unchanged.

So we (you and me, we) should at least to allow that while an initial PCR test is invalid, there are at least one and likely two, further tests that are valid, and so we can’t discount the study solely because PCR was the first step in detection.

Which makes the PCR defense a red herring, does it not?.


18 posted on 09/09/2021 1:30:16 AM PDT by blueplum ("...this moment is your moment: it belongs to you... " President Donald J. Trump, Jan 20, 2017) )
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To: Paul R.

great example, thanks :)

“Observation of school districts “hot” with flu in the past bears this out. When those districts temporarily shut down, as they usually do, flu cases drop like a rock”


19 posted on 09/09/2021 2:30:19 AM PDT by blueplum ("...this moment is your moment: it belongs to you... " President Donald J. Trump, Jan 20, 2017) )
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To: blueplum

If disseminated histoplasmosis can linger in your body only to reemerge later then why cant covid...which is just as crafty as histoplasmosis.

Its a designed bioweapon. It may do unexpected things


20 posted on 09/09/2021 3:00:02 AM PDT by RummyChick (Bagram was the most logical exit point. Stand up and justify your decision (hat tip Larrytown))
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