Immunization and immunosuppression in mice reared for high or low immune responsiveness against Nema tospiroides dubius

High (H) and low (L) immune responder mice (Sitepu & Dobson, 1982) were immunized with 5, 10, 20, 40 or 80 Nematospiroides dubius larvae, drenched 3 weeks later with anthelmintic then challenged with 100 larvae. Size of the inoculum of larvae correlated positively with the numbers of N. dubius eggs passed in the faeces of all these mice after the immunizing dose, and the size of the inoculum of immunizing larvae was negatively correlated with faecal epg, worm numbers and lengths of worms recovered from H but not L mice after challenge infection with 100 larvae. Increasing the number of N. dubius larvae in the immunizing inoculum enhanced the immunization of H mice, whereas the L mice were progressively immunosuppressed by increasing numbers of larvae