Oral Polio Vaccine linked to thousands of cases of Acute Flaccid Paralysis in India

Researchers discovered a high positive correlation between the administration of 6 or more OPV shots and the increase of AFP. They even conclude that there is good reason to suppose a causal link. 47,500 more cases of AFP than should be expected.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6121585/

Other researchers have have cited that the reasons for this over abundance of cases can be explained by the definition of AFP being broadened and more rigorous surveillance.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3559176/