[anthonyu]

Certain viruses maintained their lethality as time went on. Smallpox was very lethal throughout time. Influenza lethality ebbs throughout history. I don't think we can or should depend on less-lethal, common-cold-like symptoms from Covid-19 at any point.

[nradov]

SARS-CoV-2 does cause common cold like symptoms in the vast majority of cases, just like other coronaviruses. In particular it's quite similar to HCoV-OC43. The only reason those other endemic coronaviruses don't kill many people is that most of us get infected as children and build up some immunity.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7252012/

[rajin444]

Is there a reason we shouldn't expect it to behave like most coroanviruses?

[cortic]

There actually is. The evolutionary selection pressure on most coronaviruses exists throughout its infectious stage. So in order to be more infectious for longer the coronavirus would become less symptomatic and so less serious.

But with C19 we are aggressively isolating people with symptoms. This focuses evolutionary selection pressure on the initial infectious stage. In order to be more infectious the virus increases viral load and shedding, causing more serious symptoms; which would be an evolutionary disadvantage, except isolation renders this disadvantage moot.

Also natural immunity general focuses on the nucleus of the virus, vaccine immunity is to the spike. So this forces mutations in different proteins, which has different results.

[vimy]

Are you saying without lockdowns it would have turned in a regular cold by now?

[cortic]

Not lock-downs specifically. Testing and isolating, Maybe, but it would have cost many more lives.