Educating women in itself, going to school and learning, lowers birth rate. Not because of increased awareness about sex and contraception.

As far as allergies go, the part of the immune system which is unnecessarily acting in an allergy is primarily responsible for acting against parasitic infections, not the part which acts against viral or bacterial infections. So it would seem that improved hygeine and living conditions may be responsible for allergies.

The antibodies created by vaccinations are the same as those that would be produces if you were exposed to the disease, so there is so how is there more antibodies?