I hope nothing happens after you get your shot/vaccination.
I hope you don't have any side-effects from your vaccination.
ーI hope nothing happens after you get your shot/vaccination.
「ワクチン打った後何も起こらないといいね」
I hope nothing happens で「何も起こらないといいね」
to get one's shot/vaccination で「ワクチンを打つ」
ーI hope you don't have any side-effects from your vaccination.
「ワクチンの副作用が何もないといいね」
side-effects で「副作用」
I hope you don't have any side-effects from ... で「…の副作用が何もないといいね」
ご参考まで!