I'm not supposing it's safe in the long term. I'm supposing _nothing_ about the long term because we don't have that information. Maybe it is not safe in the long term. We'll find out some day I guess. Maybe it will lead to unexpected health _benefits_ in the long term? Who knows? So why would you weigh the potential dangers over any other potential advantages of taking it?
Anyway here are two serious questions to you:
1. Specifically how long is long enough before you'd consider the vaccine safe (compared of course to all the problems that can be caused by not taking the vaccine).
2. Do you feel ashamed allowing your fellow citizens to take on this potential risk and you forgoing when it helps end the pandemic for you and them? (Feel free to ignore this question if you are vaccinated, but are just being argumentative.)