Defense Against Invasion

Defense Against Invasion is a 1943 Disney educational live-action/animated short film.

Summary
A doctor persuades a group of boys to be vaccinated by explaining how it will protect them against disease.

Plot
A doctor persuades a group of boys to be vaccinated by explaining how it will protect them against disease. Animated sequences depict the body metaphorically as a city, defended by the blood cells, which are stimulated by vaccination to amass arms and ammunition, in order to defend the city when it is invaded by germs.