Fig 6. Predicted impact of mass vaccination with universal coverage in diverse schistosomiasis endemic settings at years 2, 12 and 22 following one, two, or three mass vaccination rounds, respectively.

By increasing the transmission parameters, different endemic settings with different contact rates—represented by the pre-vaccination host intensity in the abscissa—were generated. The absolute drop in host prevalence (panel A), absolute drop in patent snail prevalence (panel B), and the absolute drop in mean number of eggs/10-ml sample/person (panel C) are calculated at years 2, 12 and 22 by subtracting the value post-intervention from the value pre-intervention. Panel D shows the number of vaccinations needed in the first round to prevent the accrual of one new worm by persons in the community during one year after the first round of vaccination.