It is presumably good that we will have a variety of vaccines. This way if one of them has unnoticed harmful long-term effects it will only affect a subset of t

It is presumably good that we will have a variety of vaccines. This way if one of them has unnoticed harmful long-term effects it will only affect a subset of the population. Is there some sort of system like this for flu shots? Or are we injecting a large portion of the population with the exact same stuff?