Body invaders.

Presented by Dr. David Suzuki, University of British Columbia. (This series was broadcast with the following episode titles but marketed with an alternative set of titles, shown in brackets) "Body Invaders" ("Fighting Disease") Influenza and smallpox viruses compared. History of eradication of smallpox; how strain of 'flu vaccine is chosen; schistosomiasis and the human immune system; multiple sclerosis and the immune system; AIDS; study of twins in human cell vaccine experiment.