Polio is a crippling and potentially deadly infectious disease caused by a virus that spreads from person to person invading the brain and spinal cord and causing paralysis. Because polio has no cure, vaccination is the best way to protect yourself and the only way to stop the disease from spreading. The spread of polio has never stopped in Afghanistan, Nigeria and Pakistan. Poliovirus has been reintroduced and continues to spread in Chad and Democratic Republic of the Congo after the spread of the virus was previously stopped.
