A highly infectious disease, polio is caused a virus that attacks the nervous system. The virus is mainly spread through fecal contact. The virus may also be transmitted through contaminated water or water and multiplies in the intestines. Initial symptoms of polio include fatigue, fever, headache, vomiting, pain in the limbs, and neck stiffness. Infection can lead to paralysis; 1 in 200 cases lead to irreversible paralysis. Polio results in death for five to 10 percent of those who are paralyzed.
Global efforts to eradicate polio since 1988 have decreased the number of polio cases by over 99% from an estimated 350,000 cases to only 74 reported cases in 2015. Only Afghanistan and Pakistan remain polio epidemic today.
The IPV polio vaccine contains inactive polio virus strains from the three types of polio. Administered by intramuscular injection, the antibodies prevent the polio virus from spreading to the central nervous system in the event of infection.