A SIGNIFICANT number of farmers in developing countries live on the edge of sustainable livelihood. The productivity of farm animals and the economic prospects of the livestock sector in these countries are restricted by a range of factors, including pests, droughts and other environmental changes. Zoonotic diseases affect the health and productivity of livestock and that of their owners and caretakers. Brucellosis (caused by Brucella species) is one of the most widespread and important zoonotic diseases, and has free rein in many countries due to lack of awareness, knowledge, policies or appropriate use of resources. Furthermore, traditional farming practices, beliefs and food habits can contribute to the spread of the pathogen. Tools for the control and prevention of brucellosis are available, but have not been widely tested for use under the existing semi-nomadic and traditional farming conditions in former Soviet republics. Mass vaccination is the cornerstone of brucellosis control, and the Rev 1 vaccine is considered to be highly effective for use in small ruminants (Blasco 1997, Blasco and Molina-Flores 2011). The recommended strategy is mass vaccination in year 1, followed by annual vaccination of all newborn animals together with the vaccination of any non-vaccinated adults or flocks. The goal is to achieve a large coverage with a high level of protection in a short period. The question is whether this strategy is sufficiently effective to reduce the prevalence of brucellosis under less than ideal conditions. Under ideal conditions, a countrywide programme would be instigated, transborder migration, mixing and selling of infected …