National Livestock Resources Research Institute, Uganda
Uganda
Problem Statement
East Coast fever (ECF) is a devastating tick-borne disease that affects cattle productivity in sub–Saharan Africa. Currently, there is only one ECF vaccine, yet the vaccinated cattle revert to ECF pathogen reservoirs, hence promoting re-transmission. The project research is aimed at developing alternative vaccines to interfere with ECF pathogen development and transmission in ticks and/or cattle.
Progress Highlights
We are pursuing the development of live attenuated vaccines and subunit/ recombinant protein-based vaccines. We have aligned the lab for vaccine research. We are now performing cell culture studies assessing the potential of 3 DNA alkylating to induce ECF pathogen mutation. We have embarked on examining the diversity of ECF pathogens.
Key Findings
So far, Drug A has shown the potential to affect ECF-pathogen growth under culture. The drug-treated ECF pathogen has shown slow replication, suggesting that the drug could have altered the pathogen's genetic makeup, weakening it. Comparisons with the other two drugs are still to be made.
Potential Impact
This research aims to develop recombinant protein-based vaccines with the potential to block ECF-pathogen development and/or transmission in ticks.
Summary
Ticks continue to be a major reservoir and vector of a broad range of pathogens that cause diseases in animals in Africa. In this study, Dr Ndawula is keen on East Coast fever (ECF), a devastating disease affecting cattle in Africa. Dr Ndawula’s research aims to develop recombinant protein-based vaccines with a potential to block the ECF-pathogen development and/or transmission in ticks.
Grantee Description
Dr Ndawula Charles is an ARISE fellow and currently a Researcher affiliated to the Vaccinology program of the National Livestock Resources Research Institute, under the National Agricultural Research Organization in Uganda.
In 2019 he obtained his Ph.D. in Cellular and Molecular Biology from Federal University of Rio Grade do Sul, Center of Biotechnology, Porto Alegre Brazil. His Ph.D. research work was focused on developing cocktail protein-based vaccines with potential to cross-protect cattle against multiple tick species infestation, which is a common problem in Africa.
Dr Ndawula’s long-term aspiration is to develop alternative tools for control of vectors and vector-borne diseases that affect livestock and or humans. Currently, his focus is on developing recombinant vaccines that interfere ticks and their ability to transmit pathogens to humans and/or animals. He also aims to train and inspire Laboratory Technicians and young scientists from Uganda and Africa at large, as well as to contribute to establishment of a better tick research environment in Uganda.
Project: Development of Theileria parva transmission blocking universal vaccines: toward control of East Coast fever cattle-disease
East Coast fever (ECF) is caused by Theileria parva which is transmitted to the cattle during blood-feeding of the brown ear ticks (Rhipicephalus appendiculatus). Although ECF is devastating, over time field cattle (e.g., Zebu, Boran, Ankole) and buffalo native to Africa acquire immunity against tick infestation and ECF. Therefore, this project aims to identify tick and ECF-pathogen (T. parva) proteins that induce immune protection in cattle and buffalo. The protein gene-coding sequences will be used for developing recombinant proteins which will be mixed with adjuvant and administered to cattle. The vaccines will act by inducing antibodies that will neutralize the ECF-pathogens in cattle and ticks, hence blocking their transmission and development. And those that affect the tick feeding. The vaccines will significantly contribute to reduction of ECF and ECF-pathogen infected ticks and the overall tick population, hence contributing to control of ECF toward increased livestock production. Because the vaccines are not infective, and are based on conserved immunogens, they could cross-protect against all ECF-pathogen strains, hence applicable to all ECF affected areas.
