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-Signs, Portents, and the Weather-
Study shows young COVID survivors can get reinfected
2021-02-05
(HealthDay)—Being infected with the virus that causes COVID-19 is not a foolproof shield against reinfection, a small preliminary study warns.

The finding stems from tracking nearly 3,250 young U.S. Marine recruits between May and October. Of those, 189 had previously tested positive for the SAR-CoV-2 virus. During the six-week study itself, 10% of those who had tested positive got reinfected.

"You don't have a get-out-of-jail-free card just because you have antibodies from a previous infection," said study author Dr. Stuart Sealfon.

He's a professor of neurology at Icahn School of Medicine at Mount Sinai in New York City, which conducted the study in collaboration with the Naval Medical Research Center.

The findings were recently published in the preprint server medRXiv and have not been peer-reviewed.

All the Marines were beginning basic training and were initially held in Navy quarantine for two weeks, after two weeks of at-home quarantine, according to the study. Once training began, recruits were tested for COVID-19 every two weeks over a six-week period.

The result: 19 of the 189 recruits who already had COVID tested positive for a second infection during the study.

Researchers said first- and second- infections involved the same strain of the SARS-CoV-2 virus and none involved the new, more transmissible U.K., South African or Brazilian strains that have raised alarm in recent weeks.

Of 2,247 recruits who had not previously had COVID, 1,079 (48%) became infected during the study.
Posted by:Besoeker

#5  Oooooohhhh — good one, Dr. Steve!
Posted by: trailing wife   2021-02-05 12:50  

#4  Also keep in mind the reporting of the qPCR is some problematic -- COVID tests are considered positive when the PCR is positive upon being carried out to 40 cycles. Yet anyone who actually does PCR (e.g., me) knows that any cycle time above 30 or so means that one is amplifying garbage.

So the question is, of the 189 who had previously tested positive, how many of those had a cycle time threshold > 30?
Posted by: Steve White   2021-02-05 12:33  

#3  The answers from the article:

All those who tested positive during the study had "mild" symptoms, he said. None were hospitalized. But symptom risk and length of infection were the same, regardless of prior COVID history.

"The only difference was that the amount of virus on our swab tests was a little bit lower in the Marines with antibodies" from a prior infection, Sealfon said.

Reinfected Marines also had lower levels of antibodies from their initial bout, compared with Marines who didn't get reinfected.

"Two-thirds of the 19 Marines who were reinfected didn't have measurable neutralizing antibodies," Sealfon noted, suggesting that some people who get infected don't generate antibodies.


Lots to think about. Please tell me if I got anything wrong here, or missed something important:

If those who got sick the second time got less sick, had lower or no pre-reinfection levels of antibodies than those who did not get sick, and some people just don’t generate antibodies, then 1) vaccinating those with higher levels of antibodies is wasting that dose — so what is the magic number that marks true immunity? — and 2) vaccinating those who don’t generate antibodies at all is also wasting that dose, though it may be less expensive to dose everyone than to test some.

But what if the factor leading to susceptibility to reinfection is something that can easily be altered, like those vitamin levels, or getting the right mix/levels of gut bacteria? The alternative if it isn’t something that can be easily altered being that those who do not develop antibodies should not be permitted anywhere near those without adequate antibodies until after this emergency is over — possibly by deferring their basic training until after this thing calms down.

g(r)omgoru, may I suggest this as a fruitful line of inquiry for the IDF, considering how much data y’all already collect on those who’ve fallen ill. It seems to me that right now long term immunity isn’t as important as short and medium term immunity, though it would be nice. We’ve discovered that the childhood vaccines we all got sometimes do not confer lifelong immunity, and so boosters are now being recommended in middle age and beyond — Tdap (tetanus, diphtheria, and pertussis) at age 65 comes to mind, and the chicken pox vaccine to prevent the dormant virus erupting as shingles among those who had the disease as a child.

Finally and, I realize, heretically: what if the answer is to infect all recruits upon arrival, dosing all who show symptoms with the HCQ/zinc/azithromax cocktail (or something similar) to reduce severity, so as to build immunity in 90% of them? Those who afterward test below the magic antibody number could be infected a second time to see if that does the trick. And the small proportion who just don’t develop antibodies may need to be deferred until after this situation is over, or consolidated into a single group that needs to be surrounded only with those who have sufficient antibodies, to prevent them being infected yet again or be found medically unsuited to wearing the uniform altogether, no matter how otherwise suitable.

I find it is too soon upon awakening to do calculations on this information to get a better feel for the numbers — I’m sorry.
Posted by: trailing wife   2021-02-05 12:09  

#2  Good to know.

Thoughts before going to the link to see if they answered my questions there:

  • How sick did the 10% get compared to the 48% who were were getting sick the first time?

  • How sick had the 10% been the first time , ie. does being sicker the first time translate into more antibodies with which to fight off a repeat infection?

  • It was noted fairly early on that those with A type blood are more susceptible to Covid than those with O type blood. Did blood type or anything else known to impact susceptibility (for instance blood serum levels of D, A, K, zinc, etc.) correlate to susceptibility to a repeat infection?

    Now to read the thing. :-)
  • Posted by: trailing wife   2021-02-05 10:05  

    #1  35 Years of Research Into Coronavirus Infections Show Long-Term Immunity Is Unlikely
    Posted by: g(r)omgoru   2021-02-05 09:47  

    00:00