In the past two decades, viral vaccines have captured the interest and imagination of scientist and practitioner. The elimination of smallpox and the potential control of polio, measles, and other childhood diseases have overshadowed the slower progress with bacterial vaccines. This review will place bacterial vaccines in perspective and outline theoretical and practical aspects of their development and usage.
Bacterial "vaccinology" does not have an historic origin analogous to Jennerian vaccination. The first scientific attempt was Pasteur's experiments with veterinary diseases.1 Aged cultures of attenuated fowl cholera and anthrax bacilli were used to immunize susceptible animals. In both instances, these animals became remarkably resistant to challenge by virulent organisms. In parallel, and in sequence, others explored the use of killed and attenuated bacteria in the prevention of human disease. Koch discovered cell-mediated immunity during a search for tuberculosis vaccine. Von Behring and Kitasato discovered diphtheria antitoxin and passive