MODEL RELEASED. Polio vaccination. Baby receiving an oral polio vaccine, containing harmless, live strains of all three types of polio virus. The weakened viruses stimulate the patient's immune system to produce antibodies against polio, giving immunity. Polio (poliomyelitis) is an infectious disease that can permanently damage parts of the nervous system, sometimes causing paralysis. Children are vaccinated several times in their first year of life, and may receive a booster dose prior to starting school.