In the case of polio it's very clear that lead arsenic pesticide was the cause, & the rollout of the vaccine came long after cases dropped off in order to make money selling a "solution" & hide the liability of companies that had poisoned & crippled people.

While there does seem to be some evidence (assuming it's not faked) that vaccines can reduce the diseases they were designed to prevent, they also very clearly reduce the overall health of the vaccinated. The adjuvants cause chronic inflammation, auto immune issues, food allergies, etc. The kids I know who have never been vaxxed have also never had any ear infections or eczema or any of the common health issues most kids have.