Efficacy of Newcastle disease vaccines and vaccination protocols commonly used in Mali, West Africa

Newcastle disease, caused by Avian paramyxovirus -1 (APMV-1), is a devastating disease of poultry that is endemic in many countries worldwide. Several commercial vaccines and protocols are available against the disease and in most cases, they provide good clinical protection. However, despite vaccination, cases of Newcastle disease are often seen in some countries, including Mali in West Africa. Although there is only one serotype of APMV-1, eighteen different genotypes have been identified to date. The vaccine strains used in Mali belong to either genotype I (for example I-2) or II (for example LaSota and Hitchner B1) while the most recently identified isolates in Mali are from genotypes XVII and XVIII. This study was therefore undertaken to determine whether, four currently used vaccination protocols in Mali were able to protect chickens against challenges with a recently isolated genotype XVIII strain from Mali (ML008/09) and genotype IV Herts/33. The results showed clinical protection of the vaccinated birds with no shedding of ML008/09 for all of the vaccination protocols used, while shedding was detected in birds challenged with Herts/33. The data generated in this study will assist those working in the area of Newcastle disease management and control in Mali. Key words: Avian paramyxovirus-1, Newcastle disease, serology, vaccine, Mali.