5 ms·

This isn't really my area so this is conjecture and guesswork. If various immunocompromised people get infected then by a fluke their immune system could be ju

This isn't really my area so this is conjecture and guesswork. If various immunocompromised people get infected then by a fluke their immune system could be just powerful enough to contain the infection but not eradicate it, this will remain the case until the virus becomes too powerful and the host dies. It's not the absence of selective pressure that is driving the mutation here, it's the mere fact that the virus might survive the selective pressure that does it. Also from some of the explanations I've read of Covid-19 the mere duplication of the virus isn't all that damaging, the harsh way the immune system eradicates infected cells is more damaging. So someone with a limited immune response might survive for a surprisingly long time.

biophysboy 5y ago
This is closer to my area, you're basically right. Viruses copy a lot in immunocompromised people for a long time. Lots of copying is all ya need to make variants.
- ed_balls 5y ago
  Since immunocompromised people haven't "produced" super flu variant so far, is it safe to assuming we won't have it with Covid? I may spread faster, but won't be more deadly.
  - tsimionescu 5y ago
    Possibly, but spreading faster is much more deadly than being more deadly - at least for a disease that already starts at a high death rate like Covid does. This happens because living sick people help spread the disease, while dead people don't.
  - tsol 5y ago
    The general tendency is for viruses to become less deadly with increasing mutations. Highly deadly strains kill too quickly to spread well, whereas the common cold kills relatively few but hangs around long enough to keep moving from person to person. Viruses dont "care" to kill people, viruses only "want" to spread. That's what drives a viruses growth
    - ed_balls 5y ago
      That is not true for Covid. It's an upper respiratory virus which infects others before causing symptoms. It's possible to develop a variant that spreads, but kills everybody (highly unlikely in practice). There is no strong evolutionary pressure like in case of SARS-COV-1

biophysboy 5y ago

This is closer to my area, you're basically right. Viruses copy a lot in immunocompromised people for a long time. Lots of copying is all ya need to make variants.

ed_balls 5y ago
Since immunocompromised people haven't "produced" super flu variant so far, is it safe to assuming we won't have it with Covid? I may spread faster, but won't be more deadly.
- tsimionescu 5y ago
  Possibly, but spreading faster is much more deadly than being more deadly - at least for a disease that already starts at a high death rate like Covid does. This happens because living sick people help spread the disease, while dead people don't.
- tsol 5y ago
  The general tendency is for viruses to become less deadly with increasing mutations. Highly deadly strains kill too quickly to spread well, whereas the common cold kills relatively few but hangs around long enough to keep moving from person to person. Viruses dont "care" to kill people, viruses only "want" to spread. That's what drives a viruses growth
  - ed_balls 5y ago
    That is not true for Covid. It's an upper respiratory virus which infects others before causing symptoms. It's possible to develop a variant that spreads, but kills everybody (highly unlikely in practice). There is no strong evolutionary pressure like in case of SARS-COV-1