East coast fever is a fatal bovine disease caused by the apicomplexan parasite, Thieleria parva, which is transmitted by the brown ear tick Rhipicephalus appendiculatus. The disease is found in 11 countries across eastern, central and southern Africa, killing a million cattle and resulting in economic losses exceeding $300 million per year.

Cattle can be protected against ECF by a vaccination procedure known as the Infection and Treatment Method (ITM) where animals are inoculated with live T. parva sporozoites and simultaneously treated with a long-acting antibiotic. However, the vaccine is expensive and therefore other, more affordable sub-unit vaccines are needed for use in these low- resource settings.

In this discussion, we will explore:

What is wrong with the current vaccine? Does it need improvement?
How can we improve the current live vaccine?
What might be a better vaccine? What is the sub-unit vaccine and what do we know about it?
What is needed for a sub-unit vaccine to:
- Induce antibody-based immunity by targeting the sporozoites stage of the parasite?
- Induce antibody-based immunity by targeting the sporozoites stage of the parasite?
- Induce T-cell mediated immunity by targeting the schizont stage of the parasite?
- Be effective in animal/CTL models?
What are the challenges faced in developing a sub-unit vaccine?

#VKSecfever

This Keystone Symposia ePanel was co-organized with:

The views expressed in this ePanel are those of the participants and not necessarily of the participants’ organizations or of Keystone Symposia.

Henry Kimathi Kiara PhD

International Livestock Research Institute

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