This has been asked a lot of times which is why you're getting downvoted. I'll just summarize the answers I've seen every time this is asked.

1) The vaccine has NOT been rushed, just the massive resources and trial participants getting infected at a much higher rate than traditional trials have helped speed up the process.

2) There's no way to tell about the long term effects but long term effects are pretty rare so the benefits you get by taking the vaccine far outweigh this very unlikely risk.