Published online by Cambridge University Press: 05 September 2008
These observations report on the outbreak of mild to moderate Newcastle disease following LaSota vaccination at many commercial poultry layer farms in India. It is believed that this happened due to the presence of complicating pathogens in the birds, mainly mildly pathogenic avian influenza viruses (MPAI) and infectious bronchitis virus (IBV). Of the two, the principal role appeared to be that of MPAI. The reasons for the precipitation of Newcastle disease are discussed. In such cases, administration of cloned vaccine both live and killed yielded remarkable results and prevented losses. In time, the birds fully recovered. It is suggested that high titres following live and killed cloned vaccine against Newcastle disease may also protect the birds against MPAI.