It is my understanding that the early use and development of the smallpox vaccine resulted in creating the polio virus in the first place and the early use and development of the first malaria vaccine created the hiv/aids virus.
There is also strong evidence to show that the rush of drug companies to produce the child 1 dose multi disease vaccine in the late 1980’s in Western countries lead to the mass of serious peanut allergies noticed when these kids reached school age in the early 90’s. There is no evidence of this allergy in India or any of the rest of Asia.