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Viruses evolve to become more mild because very sick or dead hosts are bad spreaders. Covid has a long incubation period before symptom onset (when somebody no
by newsbinator 5y ago
Viruses evolve to become more mild because very sick or dead hosts are bad spreaders.
Covid has a long incubation period before symptom onset (when somebody notices and isolates or becomes bed-bound). So Covid, especially Delta, spreads well for days, whether or not ultimately symptoms are mild or ultimately it causes death.
Therefore a mild version of Delta wouldn't necessarily outcompete a non-mild version of Delta, all other things being equal.
- CogitoCogito 5y ago> Viruses evolve to become more mild because very sick or dead hosts are bad spreaders. This need not be true. There are many ways a virus could spread more while simultaneously making people sicker and causing more death. For example, a strain evolving to cause people to be contagious and spread for twice as long as now and then killing everyone could very well spread more than it does now.