A game called VAX! about human networks and immunology developed by Ellsworth Campbell and Isaac Bromley from Penn State University demonstrates how herd immunization can prevent epidemics. The visualization helps show how contagions can spread quickly across the human network. Concepts such as why immunization for healthy, low-risk individuals is important, why herd immunity works, and how epidemics spread are explained interactively through the game.

Play the game, read the FAQ, and learn more: VAX!