Toxoplasmosis: the first commercial vaccine.

Infection with Toxoplasma gondii can have serious consequences in pregnant women and in immunocompromised individuals. For the farming industry it is a major cause of economic loss through neonatal mortality, particularly in sheep. In the following short review, David Buxton summarizes the main features of the complex immune response to the parasite and outlines how the first commercial vaccine was developed to control toxoplasmosis in pregnant sheep. Although the vaccine is inappropriate for use in human beings, the manner in which it induces immunity in sheep will prove vital to our understanding of the infection and the eventual development of a suitable vaccine to combat toxoplasmosis in people as well as in animals.