A new-generation vaccine against schistosomiasis
Schistosomiasis is a chronic infection caused by the worm Schistosoma and estimated to affect around 200 million people worldwide. Praziquantel is the only treatment option but reinfection often occurs, particularly in young children living in endemic areas. This necessitates repeated administration of the drug, which runs the risk of generating praziquantel-resistant worms. Based on the observation that immunity to Schistosoma does develop in endemic areas, scientists of the EU-funded project 'The targeted development of a new generation vaccine for schistosomiasis' (THESCHISTOVAC) are proposing to develop a prophylactic vaccine. The vaccine will be directed against the early post-penetration skin stage larvae. In view of previous failed attempts to develop effective vaccines, the consortium is carefully selecting the candidate antigens with required characteristics in terms of expression pattern and antigenicity. To this end, they are using transcriptomic profiling of S. mansoni in 15 different stages of its life cycle, and have so far prioritised 15 proteins for vaccine development. The project website contains more information. In parallel, glycan expression profiles of all life stages have been generated and utilised to develop microarrays for serum antibody screening. Preliminary data indicate that endemic groups can be discriminated on the basis of their antibody response to certain glycans. An important line of work of the project is the establishment of a rat model of Schistosoma infection for studying immunity to early schistosomula stages. Vaccine candidates will be tested in this model for eliciting immune responses against the larvae stages of Schistosoma. Apart from advancing our understanding of schistosomiasis immunology and the protective immune mechanisms against the parasite, THESCHISTOVAC outcomes will significantly impact vaccine design. Combined with an improved research infrastructure and training of local staff, the activities of the project will hopefully improve the current toll of Schistosoma infections in sub-Saharan Africa.
