What externalities are you talking about? I fail to see how forcing women to give birth to children would do anything positive for society: either you'd have to force them to raise them, which would result in tons of children being raised by single mothers who don't want them, which doesn't sound like a very good environment (and also violates individual autonomy) and would have a lot of negative economic effects for society, or you'd end up with tons of kids in foster homes or orphanages, which would also have lots of negative economic effects for society, both for the costs of institutionalizing these children, and then later all the social problems they'll cause when they grow up and become criminals.
There are no real negative effects for vaccination, as long as you don't force them on people who have genuine medical conditions preventing them from taking them safely (e.g., allergy to vaccine components).
There are no real negative effects for vaccination, as long as you don't force them on people who have genuine medical conditions preventing them from taking them safely (e.g., allergy to vaccine components).