According to a research done by Eyal Raz, Sandip Datta and Joshua Fierer of the University of California-San Diego School of Medicine it was found that gamma radiation killed bacteria are very effective in inducing a protective immune response against the bacterial disease.
The U.S. National Institute of Allergy and Infectious Diseases also support these researches in their finding and said that these bacterial cultures could be used as vaccines. They studied the effect of irradiated Listeria monocytogenes bacteria and were astonished to find that it induced both T cell response, B cell response and provided protection against live Listeria. The study results were published in the journal Immunity.
Another advantage is that these irradiated bacterial vaccines need not be refrigerated and elicit a stronger immune response that the chemically inactivated vaccines or heat killed vaccines. NIH Director Elias A. Zerhouni, M.D said that this characteristic is of great importance in creating vaccines that are safe, effective, simple to produce and transport. These bacteria are able to trigger a strong immune response as they retain their toll-like-receptors. The experiments were mainly carried out on mice. It was also found that the protection conferred by irradiated bacterial vaccines lasted for at least a period of 12 months.