Interesting comment. Do you have a reference?
Is it known why MERS and SARS are more deadly than SARS-CoV-2?
“SARS and MERS more deadly...”
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Novel zoonotic viruses are deadly by immunological naivete.
Covid-19 looked to me like it would be as deadly as SARS but way easier to catch and to spread. Glad I was wrong.
Here is a link if you want to get specific into that:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8930171/#:~:text=The%20Severe%20Acute%20Respiratory%20Distress,case%20fatality%20rate%20of%202.13%25.
Here is a link on the nsp14 mutation:
https://www.cell.com/iscience/fulltext/S2589-0042(23)00287-0?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2589004223002870%3Fshowall%3Dtrue
ScienceDirect.com is still running open access. I have a login through Elsevier, but I think you can read there for free. On the home page in the search box labelled, “Find articles with these terms”, you should enter “nsp14 mutations” to find these and other interesting articles.
Here is an article on Covid-19 fatalities:
https://virologyj.biomedcentral.com/articles/10.1186/s12985-022-01814-1
Forgive me ifinnegan if these articles are not written for the layman, as I am not smart enough to simplify or summarize what I am reading here, though I think I understand it.