Evaluation of thermostable vaccines against Newcastle disease in village chicken used in tropics and subtropics. A review

Newcastle Disease (ND) in domestic poultry is a focus for concern throughout much of the worlds In poor rural communities because of severe economic losses that have occurred from illness. In the commercial poultry sector there are quite a number of conventional vaccines available for the control of Newcastle Disease. This has drastically reduced the incidence of Newcastle Disease in the commercial poultry farms. It is important to note here that most, if not all, of these conventional vaccines are heat labile and hence cannot be used in the rural areas since the provision of cold-chain facilities is practically impossible, coupled with the behavior of the rural scavenging chicken. An oil-adjuvant inactivated vaccine has, for some time now been used to control Newcastle Disease in rural chickens, but the vaccination coverage has always been very low because of the needed skills in its application. It is also relatively expensive with most farmers not being able to purchase it. The objectives of this study are: to evaluate ND heat resistant vaccine and if could be used successfully in a rural community (tropic and subtropic) to protect free-range chickens against ND.