[_Microft]

As far as I remember there were never serious adverse effects that did not appear within a few weeks of administration of a vaccine. The mRNA technology is conceptually even a lot simpler than other ways of vaccination. What are you exactly afraid about?

[chessmiater]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7941620/

[_Microft]

You were alluding to long term effects.

With hundreds of millions of people having received mRNA vaccines by now, we most likely have seen all the short term side effects that there are, except the rarest of them. I would not worry too much about these either.