Polio is a potentially life-threatening disease, which was once one of the most dangerous diseases in the world. In the late 1940s, an average of 35,000 people in America were disabled by polio each year. .
Polio is a potentially life-threatening disease, which was once one of the most dangerous diseases in the world. In the late 1940s, an average of 35,000 people in America were disabled by polio each year. .