The virus continues to mutate, meaning you can't make a 100% vaccine for immunity.
Small pox, polio, TB and the like they are "static" or minimal mutation meaning the vaccines work.
Mind you I've never caught Covid, I had the initial 2 vaccines, then the booster which made me feel awful, and after that thought fuck it never again.
As a frontline community worker I didn't really get to isolate so was working daily out in the community with people who's hygiene skills were not great because they are homeless and none of them followed guidelines 🤣
Tested daily on lateral flows for work never tested positive, and even recently when they stopped the lateral flows I've not been unwell.
Weirdly also my child 8 (non vaccinated) in childcare hubs and schools has never had it.
My mother a secondary school teacher, vaccinated and boosted once, has never had it.
My grandmother who has had every booster, never had it.
Were in each others company daily and were through the pandemic.
It just seems to have "missed us" somehow 🤣🤷🏻♀️