Live tularemia vaccine confers protection against lethal Legionella and Listeria infections in experimental animals.

The efficacy of a live Francisella tularensis vaccine strain to cause nonspecific immunity toward experimental legionellosis and listeriosis was studied. Immunisation with tularemia vaccine protected over 80% and 17% of experimental animals against subsequent lethal challenge with Legionella pneumophila and Listeria monocytogenes, respectively. The protection was maximal during the first month following immunisation and declined thereafter.