Yes, Y., you are right. Vacinating infants is not absurd, it does make sense. There is hard statistics confirming the value of vaccination. Just rcently, Japan relaxed its law about the MMR vaccination, and they immediately had a nation-wide surge of measles. The MMR vaccine was returned, and the incidence of measles dropped again. I have a xerox article about this, published in a peer-reviewed medical journal.
Calligraphqueen, vaccines are not really pathogens. They are antigens, identical to the antigens of pathogens, but they themselves cannot be defined as "pathogens" because they are carefully tested for NOT causing infectious disease. To prepare a vaccine, they use either live *attenuated* strains of pathogens ("attenuated" means rendered non-virulent), or killed pathogens, or chemically isolated parts of pathogens, or (more recently) genetically engineered parts of pathogens. (In the last sentence, one might add the word "former" before each mentioning of "pathogens").
It is very, very unfortunate that vaccines have side effects and children suffer from these side effects. But anaesthetics also have side effects, and so do antibiotics, and generally absolutely each and every medicine.