Infection regime showing number of worms (N) and cumulative worm exposure time (Exposure) in worm days in each of the two trickle and three control single dose infection regimes at the five culling points at which immunological measures were taken.

N and exposure are calculated assuming that the development of S. ratti adults takes 5 days following infection. Exposure is calculated as N x (Time of cull - 5) for single dose regimes and as ½ x N x (Time of cull - 5) for trickle dose regimes.*These infection regimes are the daily equivalent of iL3s administered from day 0 p.i. to (Time of cull - 5) inclusive, as detailed in the methods.