The chicken vaccine is the first fully licensed plant-cell-produced vaccine for animals in the United States and the first plant-made product to be licensed by USDA’s Animal and Plant Health Inspection Service. The vaccine contains the major immunogenic protein of the NDV and does not contain any whole NDV, live or killed. Once the chicken’s cells take up the protein in the vaccine, they trigger a protective immune response.

In granting full licensure, APHIS’ Center for Veterinary Biologics determined that the vaccine’s safety and efficacy have been satisfactorily demonstrated. The label conforms to standard precautions regarding use.

NDV occurs in many species of birds, is transmitted by inhalation and ingestion and displays wide variation in pathogenicity among strains. NDV strains are classified as asymptomatic, lentogenic (mildly pathogenic), mesogenic (moderately pathogenic) and velogenic (highly pathogenic).

NDV can be either neurotropic or viscerotropic. The neurotropic viruses cause respiratory and nervous signs. The viscerotropic viruses, which are more common, result in respiratory signs, diarrhea and swelling of the head and neck. Vaccination is the principle method of control for the mildly pathogenic strains common to the United States.

Plant-cell-produced technology represents a new generation of vaccines. First, plant-cell-produced vaccines contain no components of animal origin. Second, traditional vaccine development involves either passing a disease-producing virus through a different species or cell type until it no longer causes disease but does create immunity, or by killing the virus in a way that allows it to produce immunity but no disease in the recipient. Plant-cell-produced subunit vaccines use only specific fragments of a pathogen’s unique genetic material to stimulate a targeted immune response from the host.

Source: Animal and Plant Health Inspection Service - 2nd February 2006