Poliovirus

Polio was one of the most feared viruses in the 1940s and 1950s. Outbreaks caused more than 15,000 cases of paralysis each year until vaccines were introduced beginning in 1955. Thanks to the polio vaccine and vigilant public health efforts encouraging people to fully vaccinate their children, wild (naturally spread) poliovirus has been eliminated from the United States for more than 30 years. Poliovirus is very contagious. It is spread through person-to-person contact via the stool of an infected person or the droplets of a sneeze or cough. Most people who contract poliovirus have no symptoms. About a quarter of them have mild, flu-like symptoms such as fever, diarrhea, upset stomach and body aches. Most people may not be aware they have polio. But about 1 in 200 to 1 in 1,000 people who become infected will develop a paralytic version of the disease known as poliomyelitis. Poliomyelitis can range in severity from mild disability to acute respiratory failure and death. People who have been vaccinated against the virus have almost no chance of getting paralytic polio. Despite public health efforts to vaccinate all children against polio, some people in the U.S. may not have received the oral or injectable vaccine or gotten a full four-shot protocol.