Key facts Polio is a serious infection caused by a virus. It mainly affects children under 5 years of age. The virus can cause paralysis, and in severe cases, death. Polio is transmitted mainly through the faecal-oral route. Vaccination is the most effective way to prevent polio. Overview Polio is caused by a virus that invades the nervous system and can cause paralysis within hours. There are three types of wild poliovirus with only type 1 still circulating. Although polio is now only endemic in Afghanistan and Pakistan, the potential threat from its continued circulation means that the World Health Organization (WHO) still classifies it as a Public Health Emergency of International Concern. The Global Polio Eradication Initiative (GPEI) was launched in 1988, bringing together governments, donors, and health workers to raise awareness of the disease and improve access to polio vaccines.…