https://www.muhealth.org/our-stories/how-do-we-know-covid-19...
How does that make any sense? Don’t you think it’s more reasonable to assume we don’t know either?
And two of the available vaccines don't even give you a dead infection like most vaccines - you can't get COVID from the COVID shot (Moderna or Pfizer)
https://old.reddit.com/r/vaccinelonghaulers/
So I don't agree the effects of either are well understood.