Pros
There are lot of panel of vaccines have come for so many diseases nowadays. If we follow everything, then we need to get vaccinated for many diseases. This would definitely affect our innate and adaptive immune system. Olden days also people survived without these vaccines. Continuous vaccination may give a chance to the pathogen to get mutated with its antigenic specifity. Then, we need to find another novel vaccine.
Cons
Small pox and polio were such big tragedies we wiped off from this planet with the aid of these vaccines only. It helped us from saving our precious lives from such life threatening diseases. Therefore, development of vaccine and getting vaccinated for some important diseases will help to live healthily.
(microbiology) childhood immunizations programs have resulted in the successful global eradication of small pox in nature....