http://articles.mercola.com/sites/articles/archive/2002/12/30/dtp-vaccine.aspxIn 1949, the DTP vaccine was licensed to prevent diphtheria, tetanus, and pertussis (whooping cough) issuing forth the modern use of vaccines in the prevention of childhood illnesses. Polio immunization was later introduced to prevent that dread diseaseenCommunityServer 2008.5 SP1 (Build: 31106.3070)