For me I changed my mind based on 1 factor:
Research. I learned about how the vaccine was created, how it works, etc. While it may have short-term side effects (which we know), the concept of mRNA doesn't to me lead to some down the road horrific long term effects.
and since I'm only 58, I'll have to wait a good while anyway. But, If I could take the vaccine today, I'd do it.