In eastern Zambia, immunisation by 'infection and treatment' is the main method used to control East Coast fever, an acute and lethal cattle disease. This service, which requires a stringent cold chain, used to be free of charge. When a minimal user fee was introduced, attendance dropped drastically. Consequently, this complex immunisation programme was transferred to veterinary paraprofessionals working on their own account, with the aim of boosting a more sustainable distribution of vaccine. Paraprofessionals were provided with a motorbike and the required specific equipment, but fuel and drugs were at their expenses. The paraprofessionals recovered their costs, with a profit margin, by charging the cattle owners for immunisation. The reasons for the successful transfer of immunisation to paraprofessionals (despite the maintenance of a fee) are attributed mainly to the absence of information asymmetry between the paraprofessional and the livestock owner, the appreciable level of effort of the paraprofessionals and the verifiable outcome of the service provided.