Not OP, but this is fairly common knowledge. Here's a reliable source - search the page for VAPP: https://www.chop.edu/vaccine-education-center/vaccine-details/

Not OP, but this is fairly common knowledge. Here's a reliable source - search the page for VAPP: https://www.chop.edu/vaccine-education-center/vaccine-details/polio-vaccine https://www.chop.edu/vaccine-education-center/vaccine-detail...