3 ms·

Pre existing immunity may not preclude testing positive? Not an expert here but could preexisting immunity just mean the virus has trouble really taking hold a

Pre existing immunity may not preclude testing positive? Not an expert here but could preexisting immunity just mean the virus has trouble really taking hold and wreaking havoc before it is shut down, as opposed to never being infected at all? I guess what I’m asking is whether immunity is truly binary.

dtech 6y ago
It does. To test positive viral load needs to be at a certain level, that can only happens if cells are infected and producing virus particles. If that's happening you're not immune.
- timr 6y ago
  Current US PCR tests are set to be so sensitive that they can detect a single copy of viral RNA. This has been an under-reported fact that should be more widely known: https://www.nytimes.com/2020/08/29/health/coronavirus-testing.html https://www.nytimes.com/2020/08/29/health/coronavirus-testin...
faitswulff 6y ago
Immunity is indeed not binary. There's sterilizing vs non-sterilizing immunity, for instance, sterilizing immunity meaning that the pathogen is purged before infecting cells (emphasis mine): > Without a strong mucosal response, injected vaccines may be less likely to produce so-called sterilizing immunity, a phenomenon in which a pathogen is purged from the body before it’s able to infect cells, Dr. Durbin said. Vaccinated people might be protected from severe disease, but could still be infected, experience mild symptoms and occasionally pass small quantities of the germ onto others. https://www.nytimes.com/2020/07/14/health/coronavirus-nasal-vaccines.html https://www.nytimes.com/2020/07/14/health/coronavirus-nasal-...
sharadov 6y ago
The research says that some people may have T-cells which promote a more robust response to the virus, if their antibodies don't succeed. From the article below "This means that infected people who did not develop symptoms or antibodies may still be immune to Covid-19 via T-cells memory" It does a good job of explaining the difference between immunity acquired by antibodies vs T-cells. https://medium.com/microbial-instincts/if-antibodies-fall-short-of-covid-19-immunity-call-the-t-cells-abeb5cae6832 https://medium.com/microbial-instincts/if-antibodies-fall-sh...

dtech 6y ago

It does. To test positive viral load needs to be at a certain level, that can only happens if cells are infected and producing virus particles. If that's happening you're not immune.

timr 6y ago
Current US PCR tests are set to be so sensitive that they can detect a single copy of viral RNA. This has been an under-reported fact that should be more widely known: https://www.nytimes.com/2020/08/29/health/coronavirus-testing.html https://www.nytimes.com/2020/08/29/health/coronavirus-testin...

faitswulff 6y ago

Immunity is indeed not binary. There's sterilizing vs non-sterilizing immunity, for instance, sterilizing immunity meaning that the pathogen is purged before infecting cells (emphasis mine): > Without a strong mucosal response, injected vaccines may be less likely to produce so-called sterilizing immunity, a phenomenon in which a pathogen is purged from the body before it’s able to infect cells, Dr. Durbin said. Vaccinated people might be protected from severe disease, but could still be infected, experience mild symptoms and occasionally pass small quantities of the germ onto others. https://www.nytimes.com/2020/07/14/health/coronavirus-nasal-vaccines.html https://www.nytimes.com/2020/07/14/health/coronavirus-nasal-...

sharadov 6y ago

The research says that some people may have T-cells which promote a more robust response to the virus, if their antibodies don't succeed. From the article below "This means that infected people who did not develop symptoms or antibodies may still be immune to Covid-19 via T-cells memory" It does a good job of explaining the difference between immunity acquired by antibodies vs T-cells. https://medium.com/microbial-instincts/if-antibodies-fall-short-of-covid-19-immunity-call-the-t-cells-abeb5cae6832 https://medium.com/microbial-instincts/if-antibodies-fall-sh...