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And that theory about viruses becoming less deadly isn't an universal rule in the first place. For example, smallpox and measles never got less deadly. In many
by ufo 5y ago
And that theory about viruses becoming less deadly isn't an universal rule in the first place. For example, smallpox and measles never got less deadly. In many cases, the virus becoming less deadly is because the population acquired immunity from vaccinations or previous infection, not because the virus evolved that way.
In the case of covid, one important thing to consider is that people are the most infectious before they develop severe symptoms. Therefore, there is less selective pressure towards making it less severe.
- orblivion 5y agoI wonder if there's extra selective pressure among relatively smart creatures like us. Supposing there's a really nasty disease that manifests after a week, and we're contagious for a few days before. Eventually we'll get wind of it and start being more careful. If it's a less nasty virus, we just won't care enough and let it spread.
- nsxwolf 5y agoIt does seem to be true of respiratory viruses though. Asiatic flu is still around, probably HCoV-OC43, now a nearly harmless common cold virus. Spanish flu is still dangerous like all flus, but not the killer that it was. It would be odd if this is the one, the permanently deadly respiratory virus that just never gives humanity a break, for ever and ever.
- ufo 5y agoBut is HCoV-OC43 harmless because the virus became less deadly, or because everyone has immunity from being infected by it when they were still children?