Adaptive radiation within the vaccine target tetraspanin-23 across nine Schistosoma species from Africa

► There is antigenic variability within exposed regions of the tetraspanin 23 protein. ► This is indicative of adaptive responses of schistosome species to the host immune system. ► Adaptive radiation occurring between schistosome species. ► The high levels of diversity in TSP23 questions its utility as a vaccine target.