Leishmaniasis is a protozoon parasitic infection transmitted by sand flies that infects up to 2 million people worldwide annually. If left untreated it can cause considerable cutaneous scarring and soft tissue destruction, and visceral leishmaniasis can be fatal. Current treatment regimes involve the administration of drugs, but so far the disease has evaded attempts to develop a vaccine against it.

In August 6 Journal of Experimental Medicine Jesus Valenzuela and colleagues at the National Institute of Allergy and Infectious Disease, Bethesda, USA report on the development of a potential Leishmania vaccine based on a protein found in the saliva of the insect vector that transmits the disease.

Valenzuela et al. characterized nine salivary proteins extracted from Phlebotomus papatasi — the vector of Leishmania major — by standard SDS electrophoresis. They identified a 15 kDa protein, subsequently named SP15, that seemed to protect vaccinated mice challenged with parasites and vector...