I've seen people at work become much more unwell from the vaccine than I was from covid, as in in bed level of unwell. I'm younger than them and have read that younger people and people who have had covid have worse side effects.
This is the main reason for me.
I had the virus which for me was nothing more than a couple of days of stomach pains. If an older relative hadn't been experiencing the same thing I wouldn't have bothered testing.
Meanwhile the two people I know under 30 who've been vaccinated wish they hadn't bothered. Both really ill, one ended up in hospital and now has constant migraines having never suffered one before.
So either one (covid vs vaccine) seems like a bit of a gamble to me.
Covid: I might catch it again, and I might become ill to the point I miss work.
Vaccine: I will have it, and I might become ill to the point I miss work.
I'd rather choose the one where there are two "mights" instead of one.
That's the main reason really, but the emergency approval and lack of long term data tip me further into the take my minuscule chances with the virus camp.
Your question on when I'll change my mind:
If it's still a thing when I'm older, or I put on a lot of weight, or I develop an illness / disease that makes me especially vulnerable to covid then I might. That would depend on what specific vaccine I was offered and if the company was still protected from legal action / liability.