11 ms·

Does the existence of this protein explain asymptomatic infections? I wonder what percentage of the population have it.

jcynix 4y ago
Everyone has it (produced) when needed, as far as I can derive from https://en.wikipedia.org/wiki/Leucine_rich_repeat_containing_15 https://en.wikipedia.org/wiki/Leucine_rich_repeat_containing... But maybe different people generate different amounts at different speeds?
superkuh 4y ago
It's very unlikely. Asymptomatic infections of aerosol spread respiratory diseases are not exclusive to sars-cov-2. Most people get asymptomatically infected with Influenza a every single year and often infect others without even realizing it. The more likely guess is that once you have humoral/serum immunity to protect the body proper you just get the upper respiratory infection (since mucosal tissues are not protected by humoral immunity significantly). And that mucosal only infection is less likely to cause serious disease.
logifail 4y ago
> Does the existence of this protein explain asymptomatic infections? I wonder what percentage of the population have it. Our [unvaccinated] 8 year-old had Covid last Spring and his symptoms lasted exactly one entire morning. PCR swab tests were done in school on day 1, on day 2 I got a frantic phone call from his school at 7am saying "keep him home, he has Covid!". We would not otherwise have known, since he had precisely a bit of a headache. No cough, no fever. He took a paracetamol and sat in front of the TV. By the afternoon the headache was gone. He tested PCR positive again on day 6, so got to enjoy the full 10 days' mandatory isolation, thanks to the rules in place here at that time. The interesting question is: what percentage of young and/or healthy people actually had a severe case of Covid? We know an awful lot of people who've had mild-to-insignificant cases...
- incangold 4y ago
  From the point of view of someone who is immunocompromised this seems like the bare minimum we can do as a society to protect the vulnerable. Something between “almost nothing” and “nobody leaving the house” would be nice. At the moment we’re at “almost nothing”.
  - sokoloff 4y ago
    Isolating and denying effective schooling to every kid who comes down with a one-day mild illness for ten days does not seem like a risk-proportionate response to me.
    - aflag 4y ago
      Why not? I don't think skipping one week and a half of school when you're 8 will have any real effect in your life neither in the short or long term future. Meanwhile, if they get in contact with someone with some sort of immunodeficiency along the way it could cause irreparable damage.
      - callahad 4y ago
        > one week and a half of school when you're 8 I think you're vastly underestimating how often kids exhibit symptoms potentially consistent with Covid during a school year.
        neoromantique 4y ago
        How often do they exhibit symptoms AND trigger a PCR test?
        callahad 4y ago
        Oh sure. I think we're interpreting the parent comments differently (i.e., I'm understanding sokoloff's and aflag's comments to be about more general precautionary isolation based on symptomatic illness, not necessarily PCR-confirmed infection like logifail's kid.)
PartiallyTyped 4y ago
It seems that everyone has it to varying degrees, however it probably doesn’t seem to explain asymptomatic infections unless the virus has the capacity to shed the protein which doesn’t seem to be the case, or that people with asymptomatic infection produce enough of this protein that sars-covid-19 has hard time accumulating and causing the disease, and an asymptomatic patient spreads the virus to people who produce far less of this protein. According to the authors the protein binds “like velcro” effectively immobilising and preventing infection. Symptoms would occur if sufficient cells were infected thus the second case sounds plausible to a degree. I am not a virologist so take everything with a huge grain kf salt.

Everyone has it (produced) when needed, as far as I can derive from https://en.wikipedia.org/wiki/Leucine_rich_repeat_containing_15 https://en.wikipedia.org/wiki/Leucine_rich_repeat_containing... But maybe different people generate different amounts at different speeds?

superkuh 4y ago

It's very unlikely. Asymptomatic infections of aerosol spread respiratory diseases are not exclusive to sars-cov-2. Most people get asymptomatically infected with Influenza a every single year and often infect others without even realizing it. The more likely guess is that once you have humoral/serum immunity to protect the body proper you just get the upper respiratory infection (since mucosal tissues are not protected by humoral immunity significantly). And that mucosal only infection is less likely to cause serious disease.

logifail 4y ago

> Does the existence of this protein explain asymptomatic infections? I wonder what percentage of the population have it. Our [unvaccinated] 8 year-old had Covid last Spring and his symptoms lasted exactly one entire morning. PCR swab tests were done in school on day 1, on day 2 I got a frantic phone call from his school at 7am saying "keep him home, he has Covid!". We would not otherwise have known, since he had precisely a bit of a headache. No cough, no fever. He took a paracetamol and sat in front of the TV. By the afternoon the headache was gone. He tested PCR positive again on day 6, so got to enjoy the full 10 days' mandatory isolation, thanks to the rules in place here at that time. The interesting question is: what percentage of young and/or healthy people actually had a severe case of Covid? We know an awful lot of people who've had mild-to-insignificant cases...

incangold 4y ago
From the point of view of someone who is immunocompromised this seems like the bare minimum we can do as a society to protect the vulnerable. Something between “almost nothing” and “nobody leaving the house” would be nice. At the moment we’re at “almost nothing”.
- sokoloff 4y ago
  Isolating and denying effective schooling to every kid who comes down with a one-day mild illness for ten days does not seem like a risk-proportionate response to me.
  - aflag 4y ago
    Why not? I don't think skipping one week and a half of school when you're 8 will have any real effect in your life neither in the short or long term future. Meanwhile, if they get in contact with someone with some sort of immunodeficiency along the way it could cause irreparable damage.
    - callahad 4y ago
      > one week and a half of school when you're 8 I think you're vastly underestimating how often kids exhibit symptoms potentially consistent with Covid during a school year.
      - neoromantique 4y ago
        How often do they exhibit symptoms AND trigger a PCR test?
        callahad 4y ago
        Oh sure. I think we're interpreting the parent comments differently (i.e., I'm understanding sokoloff's and aflag's comments to be about more general precautionary isolation based on symptomatic illness, not necessarily PCR-confirmed infection like logifail's kid.)

PartiallyTyped 4y ago

It seems that everyone has it to varying degrees, however it probably doesn’t seem to explain asymptomatic infections unless the virus has the capacity to shed the protein which doesn’t seem to be the case, or that people with asymptomatic infection produce enough of this protein that sars-covid-19 has hard time accumulating and causing the disease, and an asymptomatic patient spreads the virus to people who produce far less of this protein. According to the authors the protein binds “like velcro” effectively immobilising and preventing infection. Symptoms would occur if sufficient cells were infected thus the second case sounds plausible to a degree. I am not a virologist so take everything with a huge grain kf salt.