Development of a vaccine against Schistosoma japonicum in China: a review.

Significant progress has been made over the past 50 years in the control of schistosomiasis japonica in China. However, recent data suggest that the disease is re-emerging. By the end of 2003, Schistosoma japonicum was still endemic in 110 counties in seven provinces in the southern part of China where the long-term reduction of the disease has been replaced by an increase in the number of people infected and areas infested by the intermediate host snail, i.e. Oncomelania hupensis. Explanations are multifactorial, including the construction of the Three Gorges dam, major flooding events, recovery of the Dongting Lake and the possible impact of climate change. An efficacious vaccine against S. japonicum would represent a significant addition to the current arsenal of control tools, particularly in the framework of an integrated control approach. The vaccine could be targeted either towards the prevention of infection or towards the reduction of parasite fecundity. Although progress in this field has been relatively slow, encouraging results have been obtained in recent years using defined native and recombinantly derived S. japonicum antigens. These findings suggest that development of a safe and efficacious vaccine is feasible. This paper reviews the progress in the development of a vaccine against S. japonicum in China, and includes also data from foreign researchers who are engaged in collaborative work with Chinese scientists.