Dr. Kirimanjeswara studies bacteria that cause disease in humans, and how the immune system fights against these microbes. Selenium is a trace element that is found naturally in various environments, and Dr. Kirimanjeswara has become interested in the involvement of selenium in infectious disease. Dr. Kirimanjeswara discusses trace elements, whooping cough, as well as his former life as a veterinarian, and the importance of vaccination.