Sheep and goat pox: literature review about vaccine effectiveness

Live attenuated, inactivated, and combination vaccines consistently reduce the impacts of sheep pox virus in sheep and goat populations. Studies report that live attenuated vaccines produce protection rates of 80–100% over periods ranging from several weeks to 52 months. For example, one study noted 100% protection in sheep using the RM-65 strain for 2.5 months, while another documented 100% protection lasting up to 52 months in goats vaccinated with the goat pox virus/Uttarkashi/1978 formulation. Inactivated vaccines, when administered at high doses, have yielded 100% protection for durations of up to 9 months and offer improved safety for more sensitive animals. Combined or bivalent vaccines also achieve complete protection in most trials. In contrast, unvaccinated controls have shown morbidity as high as 100% and mortality up to 72%. Reports further indicate that breed, age, and physiological factors influence vaccine effectiveness, with some exotic breeds showing less robust responses to live attenuated formulations.