trypanosomiasis vaccine trypanosomiasis vaccine a trypanosomiasis vaccine is a vaccine against trypanosomiasis. no effective vaccine currently exists, but development of a vaccine is the subject of current research. the bill & melinda gates foundation has been involved in funding research conducted by the sabin vaccine institute and others. there are many obstacles to development of such a vaccine. one obstacle is variant surface glycoprotein which makes it difficult for the immune system to recognize the infectious organism. also, trypanosoma brucei has a direct inhibitory effect upon b cells. it has been suggested that these challenges could be overcome by a vaccine against the initial antigens, or generating an immune response against the cysteine protease (for example, cruzipain). an effective vaccine was achieved in 2021 using a mouse model of infection with trypanosoma vivax.