Immunization of marmosets with Trypanosoma cruzi cell surface glycoprotein (GP90).

Marmosets (Callithrix jacchus) have been immunized with a vaccine comprising a Trypanosoma cruzi 90K cell surface glycoprotein and the adjuvant saponin; a combination previously shown to be protective in mice. Immunization was by two s.c. injections one month apart and non-lethal challenge of homologous Y strain T. cruzi was given one month after the booster immunization. No anti-T. cruzi antibodies were detected after the first immunization but high levels developed after boosting. Immunization caused a significant decrease in the levels of acute phase blood parasitaemia, however, both immunized and control animals remained xenodiagnosis positive 60 weeks after infection. No ECG aberrations, histopathological lesions or anti-tissue antibodies were detected in infected marmosets.