Clearly, for anyone who's had negative effects, it's not a good thing. God willing everyone does as well as possible and doesn't suffer serious side effects.
But we must remember the science and statistics at play here. The vaccine isn't 100.000000% safe. Nobody said it was. No medical intervention ever is. But the point is, the global scientific community and regulatory agencies are in solid agreement that the harms of the vaccine are outweighed by those of the virus.
And that's all this is. A balance of risk. Unfortunately some will suffer.
If our future over the next few years is repeat vaccinations, then the pharma R&D effort will continue to improve the safety & performance of these vaccines. Our knowledge will improve and the ability to match certain vaccines & treatments to certain groups, will mean fewer & fewer side effects / better outcomes.