Trial to Investigate the Effect of Schistosoma Mansoni Infection on the Response to Vaccination With MVA85A in BCG-vaccinated African Adolescents

Mycobacterium tuberculosis (M. tb) is a pathogen with worldwide distribution which infects humans causing tuberculosis (TB), a transmissible disease resulting in very high mortality and morbidity; development of an effective vaccine is a global health priority.

Over a billion people worldwide are infected with one or more helminths. Helminths are parasitic worms, of which Schistosoma mansoni is one species. There is some evidence that helminth infection may affect a person's response to a vaccine. In this trial the investigators hope to investigate whether Schistosoma mansoni infection affects adolescents' responses to a candidate TB vaccine called MVA85A, as adolescents are a crucial target group for an effective TB vaccine.