Among them, 637 cases (96.7%) had received three or more doses of polio vaccine before being diagnosed with AFP; two cases (0.3%), both in the 5–9 year age group, were completely unvaccinated; and a further 20 cases (3.0%) had received less than three doses, including 16 under-vaccinated cases older than 6 months. This evidence concerns the gene AFP and poliomyelitis.