5 ms·

We have been running a "natural" trial on millions of people. From that, we can already tell that reinfection, although possible, is very rare.

acqq 6y ago
> From that, we can already tell that reinfection, although possible, is very rare. No. From the current papers, we just know that the reinfection where people have had their virus sequenced in both first and second infection is very rare. The problem is technological. Up to now there are around 50 million confirmed cases in the world but probably less than 100 thousand sequencings performed, and only a few sequencings by those who had strong enough symptoms twice and had the chance to have sequencing twice. Without sequencing one just can’t prove that some case is an actual reinfection. All other cases are just “possible” (i.e. unprovable) reinfections and nobody can claim anything worthy of a scientific paper about them.
macintux 6y ago
Can we really? Infection itself is still somewhat uncommon, thanks to the global reaction to the pandemic. I don't doubt that reinfection will be rare, at least over the span of a few months, but to my mind that would seem unproven given how hard we're (generally) working to keep people from being infected in the first place.
- krona 6y ago
  In many countries, healthcare workers are exposed (to varying degrees) on a daily basis.
  - Symmetry 6y ago
    Good point. I'd hope they'd receive regular testing as well.
    - kaitai 6y ago
      Unfortunately, your hope is unfounded. My spouse is a physician and when coughing (acute bronchitis) could not get a test without job consequences (being forced to take 10 days off and reschedule all patients regardless of the outcome of the test). There has been an exposure in a neighboring ward through a fellow healthcare worker and tests are not being made available broadly. Remember, in the US healthcare workers generally have to go through insurance to get approved for tests, etc., even though they work in healthcare -- they're not at this time provided anything more than the general public in terms of diagnostics. (At least spouse gets free masks at work, haha...)
  - rusk 6y ago
    Yes ... and they are getting reinfected. The fatality rate among medics is quite high relative to general population
    - krona 6y ago
      The fatality rate among medics is quite high relative to general population 'Quite high' could mean anything, but if you're implying 'higher than' then that isn't supported by the statistics I've seen in a dozen countries.
Symmetry 6y ago
I'm not sure we can rule out the idea that reinfection after 6 months is common but almost always asymptomatic in people with healthy immune systems. There was that British common cold coronavirus challenge trial where most subjects could be reinfected after 1 year, confirmed by PCR, but none of them developed symptoms.
- acqq 6y ago
  Which could mean that such asymptomatic people could still infect somebody vulnerable, if they shed enough virus at some point of their reinfection. The open question is, again, what will be the percentage of such cases.
  - SomeoneFromCA 6y ago
    Unfortunately there are several taboos on many forums, regarding discussion Covid. For ex.: Covid reinfections, lab origins of covid etc.
    - acqq 6y ago
      SARS-CoV-2 has not been created in the lab. The genome looks completely different than such.
      - anoncake 6y ago
        How do you identify a lab-created virus?
        SomeoneFromCA 6y ago
        Of course there is no way. I think people need to start relaxing. Trump has lost, so stop being afraid talking about the lab origins of Covid.
      - SomeoneFromCA 6y ago
        Yeah, exactly what I was talking about. There is no way to say this just by looking at the genome, all you can do is to say that is not very probable, and that would still be a dubious claim. There is a plenty of gnome manipulations that leave no trace. Having said that, lab origin does not neccesarily mean genetic manipulation. Serial passage through animals (say, minks) will leave no trace of genetic engineering, but may make the virus contagius to humans (minks and humans have similar ACE2 receptor). Or just poorly handled sample from the would do.
kaitai 6y ago
There is a temporal component here. As an ancestor commenter said, "you can't catch it again right away" (emphasis added). We do not know (because we cannot know) if reinfection is possible after two years, for instance, because we have not had the virus for two years yet.
- rusk 6y ago
  Don’t forget there are lifestyle factors that can effect your immune response. You’ll typically fight off a cold except for that one time when it catches you tired, or stressed ...
SomeoneFromCA 6y ago
Do you know how academic, narrow and unpractically stiff are criteria for a proof of reinfection? You need to have the viral genome sequenced TWO times, and both times it must be a slightly DIFFERENT virus. In that context "very rare" is not a useful term.

acqq 6y ago

> From that, we can already tell that reinfection, although possible, is very rare. No. From the current papers, we just know that the reinfection where people have had their virus sequenced in both first and second infection is very rare. The problem is technological. Up to now there are around 50 million confirmed cases in the world but probably less than 100 thousand sequencings performed, and only a few sequencings by those who had strong enough symptoms twice and had the chance to have sequencing twice. Without sequencing one just can’t prove that some case is an actual reinfection. All other cases are just “possible” (i.e. unprovable) reinfections and nobody can claim anything worthy of a scientific paper about them.

macintux 6y ago

Can we really? Infection itself is still somewhat uncommon, thanks to the global reaction to the pandemic. I don't doubt that reinfection will be rare, at least over the span of a few months, but to my mind that would seem unproven given how hard we're (generally) working to keep people from being infected in the first place.

krona 6y ago
In many countries, healthcare workers are exposed (to varying degrees) on a daily basis.
- Symmetry 6y ago
  Good point. I'd hope they'd receive regular testing as well.
  - kaitai 6y ago
    Unfortunately, your hope is unfounded. My spouse is a physician and when coughing (acute bronchitis) could not get a test without job consequences (being forced to take 10 days off and reschedule all patients regardless of the outcome of the test). There has been an exposure in a neighboring ward through a fellow healthcare worker and tests are not being made available broadly. Remember, in the US healthcare workers generally have to go through insurance to get approved for tests, etc., even though they work in healthcare -- they're not at this time provided anything more than the general public in terms of diagnostics. (At least spouse gets free masks at work, haha...)
- rusk 6y ago
  Yes ... and they are getting reinfected. The fatality rate among medics is quite high relative to general population
  - krona 6y ago
    The fatality rate among medics is quite high relative to general population 'Quite high' could mean anything, but if you're implying 'higher than' then that isn't supported by the statistics I've seen in a dozen countries.

Symmetry 6y ago

I'm not sure we can rule out the idea that reinfection after 6 months is common but almost always asymptomatic in people with healthy immune systems. There was that British common cold coronavirus challenge trial where most subjects could be reinfected after 1 year, confirmed by PCR, but none of them developed symptoms.

acqq 6y ago
Which could mean that such asymptomatic people could still infect somebody vulnerable, if they shed enough virus at some point of their reinfection. The open question is, again, what will be the percentage of such cases.
- SomeoneFromCA 6y ago
  Unfortunately there are several taboos on many forums, regarding discussion Covid. For ex.: Covid reinfections, lab origins of covid etc.
  - acqq 6y ago
    SARS-CoV-2 has not been created in the lab. The genome looks completely different than such.
    - anoncake 6y ago
      How do you identify a lab-created virus?
      - SomeoneFromCA 6y ago
        Of course there is no way. I think people need to start relaxing. Trump has lost, so stop being afraid talking about the lab origins of Covid.
    - SomeoneFromCA 6y ago
      Yeah, exactly what I was talking about. There is no way to say this just by looking at the genome, all you can do is to say that is not very probable, and that would still be a dubious claim. There is a plenty of gnome manipulations that leave no trace. Having said that, lab origin does not neccesarily mean genetic manipulation. Serial passage through animals (say, minks) will leave no trace of genetic engineering, but may make the virus contagius to humans (minks and humans have similar ACE2 receptor). Or just poorly handled sample from the would do.

kaitai 6y ago

There is a temporal component here. As an ancestor commenter said, "you can't catch it again right away" (emphasis added). We do not know (because we cannot know) if reinfection is possible after two years, for instance, because we have not had the virus for two years yet.

rusk 6y ago
Don’t forget there are lifestyle factors that can effect your immune response. You’ll typically fight off a cold except for that one time when it catches you tired, or stressed ...

SomeoneFromCA 6y ago

Do you know how academic, narrow and unpractically stiff are criteria for a proof of reinfection? You need to have the viral genome sequenced TWO times, and both times it must be a slightly DIFFERENT virus. In that context "very rare" is not a useful term.