Antibody responses in rats infected with Angiostrongylus cantonensis and the passive transfer of protective immunity with immune serum.

Little haemagglutinating antibody was detected in the serum of rats with primary Angiostrongylus cantonensis infections until the juvenile worms left the brain and lodged in the lungs about 35 days after infection. Antibody titres reached a peak 50 days after infection and were maintained for at least a further 95 days. Increasing the infective dose of A. cantonensis larvae increased the peak antibody titres attained by the infected rats. Re-infection temporarily reduced the serum antibody titre, but later it increased and showed an anamnestic response. Reaginic antibody production was transient during primary infections; re-infection failed to stimulate further reaginic antibody production. Antiserum from immune donor rats protected recipients against A. cantonensis. The transferred immune serum suppressed anti-A. cantonensis antibody production in recipient rats.