This interactive feature from the NOVA: "Surviving AIDS" Web site shows how a normal immune system has to work very hard to fight off an invading virus, and then explains how that task is made thousands of times more difficult for someone who is HIV positive — i.e. someone whose immune system is deficient. This is an excellent resource for classes discussing AIDS.
NOVA, Teachers' Domain
• Lesson Plans • Pictures and/or Illustrations
• Middle School
WGBH Educational Foundation