Pioneering Subunit Vaccine Candidates Against Animal African Trypanosomiasis

Caused by the protozoan parasites Trypanosoma vivax and Trypanosoma congolense, AAT is responsible for the death of 3m cattle each year, causing chronic anemia, weight loss, reduced milk production, and high mortality rates, resulting in billions of dollars in lost agricultural output annually. 

For decades, developing an effective vaccine against trypanosomes was widely regarded as an almost insurmountable challenge. The parasites survive by utilizing sophisticated antigenic variation, rapidly and continuously altering their surface coat proteins to stay one step ahead of the host’s immune system and render immune responses ineffective.

At the York Biomedical Research Institute (YBRI), Professor Gavin Wright and his research team are breaking through this barrier by identifying invariant surface proteins that the parasite cannot readily mutate. A key milestone in this effort was achieved in a study by Autheman et al. (Nature, 2021), which demonstrated that targeting a single, conserved cell-surface antigen — the invariant flagellum antigen (IFX) on T. vivax — could induce robust protective immunity in model systems. 

Building upon these results, Professor Wright’s ongoing project focuses on translating these findings into viable livestock vaccines for cattle. By proving that the immune system can be trained to recognize non-variable parasite targets, this research offers real hope for a scalable vaccine that could safeguard livestock and support farming livelihoods across sub-Saharan Africa.