Polio, or poliomyelitis, is a disabling and life-threatening disease caused by the poliovirus. The virus spreads from person to person and can infect a person’s spinal cord, causing paralysis (can’t move parts of the body). Most people who get infected with poliovirus will not have any visible symptoms. About 1 out of 4 people (or 25 out of 100) with poliovirus infection will have flu-like symptoms that can include: Sore throat Fever Tiredness Nausea Headache Stomach pain These symptoms usually