Reported cases and incidence of Poliomyelitis are derived from official country reporting to the World Health Organization (WHO). Data are updated and made available annually mid-July.
These data are used to provide global trends over time, and to inform the Strategic Advisory Group of Experts on Immunization (SAGE) and other advisory bodies to make evidence-based decisions as they deliberate different policies (for example, the need for booster doses, and targeted ages).