[zerobits]

You would think – but viruses don't necessarily become less deadly.

The virus wants to maximize transmissibility, and that might require trading off further against the host's health and increasing its death rate.

An example is Myxoma virus. It was intentionally introduced to pest Australian rabbit populations (to cull them) and studied.

After ~30 years of evolution, they found the dominant strain had a 70-95% death rate and left long-lasting lesions. Other strains with higher (~99%) and lower (~50%) death rates weren't as stable & prevalent.

Once a virus is transmitted (enough), what happens to the health of its host is irrelevant.

[1] https://www.sciencedirect.com/topics/immunology-and-microbio...

[libertine]

It basically needs to be extremely contagious without symptoms that stop the spread - like killing the host.

Which in part this virus has, asymptomatic and pre-symptomatic are as contagious as symptomatic. If it's enough to spread, doesn't matter much if the host dies after a few days or not.

[tonyedgecombe]

>Which in part this virus has, asymptomatic and pre-symptomatic are as contagious as symptomatic.

Do we really know that yet?

[libertine]

>Infectiousness may peak before symptom onset (7). Viral loads appear to be similar between asymptomatic and symptomatic patients (8), although the implications for infectiousness are unclear. People experiencing symptoms may self-isolate or seek medical care, but those with no or mild symptoms may continue to circulate in the community. Because of this, those without severe symptoms have the potential to be “superspreaders” and may have an outsized influence on maintaining the epidemic.

Source: https://science.sciencemag.org/content/370/6515/406

While it's not confirmed they are more infectious, they walk among the community without being aware, therefore more prone for spreading.