Growing up in the rolling hills of Nyandarua County, Hannah Chege’s childhood was deeply shaped by her family’s small herd of dairy cows. These cows were more than just livestock to her family; they were a vital source of income, providing milk that helped cover school fees and put food on the table. However, their livelihood was constantly under threat from East Coast Fever (ECF), a deadly cattle disease that devastated her family’s herd.
As a child, Hannah spent many hours on the farm, helping her father care for the cows. Part of her responsibilities involved handpicking ticks off the cattle, as her father warned her that the ticks were responsible for spreading a deadly disease. It wasn’t until she joined veterinary school that she fully understood the gravity of the situation—she was dealing with ECF, a disease that could destroy their entire livelihood.
This early experience sparked a profound curiosity in Hannah to understand and find solutions to combat ECF. Now, as a PhD student at the University of Nairobi’s Faculty of Veterinary Medicine, she is dedicating her research to developing an alternative vaccine to combat this devastating disease. Her work focuses on creating a subunit vaccine that could potentially save the lives of countless cattle and protect the livelihoods of farmers across Africa.
ECF is caused by Theileria parva, a parasite spread by ticks. The disease is a major threat to livestock in many parts of Africa, and it is estimated that over a million cattle die from it annually. This not only causes financial loss to farmers but also impacts food security and the economy. Current efforts to control ECF rely on the Infection and Treatment Method (ITM), which uses a live parasite and an antibiotic to prevent the disease. However, this method has several limitations: it requires cold-chain storage (often using liquid nitrogen), is expensive, and must be administered by trained personnel.
To address these challenges, Hannah’s research seeks to create a more affordable and accessible solution. She is working on a subunit vaccine, which uses protein parts of the Theileria parva parasite, called antigens, to trigger an immune response in cattle without the need for live parasites or antibiotics. By focusing on specific proteins found in parasites related to Theileria parva, such as those responsible for malaria (Plasmodium falciparum) and other cattle diseases, Hannah has been able to identify new antigens that could be used to create the subunit vaccine.
Her research led her to identify four novel proteins from T. parva, and by vaccinating cattle with these proteins, she was able to trigger a strong immune response. She then extracted the serum from the cattle, which contained antibodies, and tested how effectively these antibodies could block the infection-causing parasite. The results have been promising, as her work has identified six potential vaccine candidates a “cocktail” of newly discovered antigens combined with previously known ones.
The development process is not without its challenges. For instance, the long incubation periods required for testing can stretch over several weeks, and working with delicate sporozoites (the infective form of the parasite) is difficult, as they can easily die when stored in frozen material. Despite these hurdles, Hannah remains determined to continue her research, motivated by the memories of seeing her family’s cows suffer and die from ECF.
Beyond the lab, Hannah is also involved in a program called the Feed the Future Innovation Lab for Animal Health (AHIL). This initiative, implemented in Narok County, aims to improve human nutrition and economic welfare by addressing cattle health challenges. The program is a collaboration between Washington State University, the University of Nairobi, the International Livestock Research Institute, and several Kenyan research organizations. It combines laboratory and field studies to enhance the adoption of animal health interventions and assess their impact on household well-being.
With the support of her mentors and the resources provided by AHIL, Hannah is not only contributing to scientific advancements but also working to directly improve the lives of farmers like her family. While the road to developing a new vaccine may be long and complex, Hannah’s vision is clear: a future in which ECF is no longer a death sentence for cattle or a financial catastrophe for families. Her dedication to this cause, rooted in her personal experiences and her scientific expertise, continues to inspire hope for a more resilient future for livestock farmers across Africa.
