in that regard, the word safe is impossible for something to be, nothing would be considered safe everything has a potential side effects. peanuts, advil, the sun, water (if you think thats dumb, just go to Mexico and drink from the tap) even the miracle drug Ivermectin... Just about eveything that enters your body can be considered unsafe, thats just a foolish statement.
There were side effects that were not disclosed or breezed over (such as the heart issues) and things we were told about the vaccine that were patently untrue such as that it would stop transmission of the virus.
Things like that play right into the hands of conspiracy theorists
edit: I took the vaccine because I know that ALL vaccines have that capability and I obviously felt that the rewards outweighed the risks substantially despite the fact that I have had Guillain-Barre' and can't even take the flu shot