Studies with a duck embryo adapted goose parvovirus vaccine.

A goose parvovirus isolated from goslings with Derzsy's disease was adapted to growth in embryonating duck eggs. After 22 passages the adapted parvovirus was evaluated in 1 to 3-day-old susceptible goslings for attenuation and immunogenicity. The response to vaccination was measured by virus neutralisation (VN) tests and resistance to experimental challenge. The results showed that the duck embryo adapted parvovirus vaccine was apathogenic for goslings and stimulated significant VN antibody levels for up to 20 weeks. Virus was reisolated from the faeces of vaccinated goslings for up to 3 weeks after vaccination. In contact control goslings remained serologically negative until 6 weeks after contact when low levels of antibody were detected. Goslings vaccinated subcutaneously were resistant to experimental challenge 2 days after vaccination. Vaccination of goslings by subcutaneous and foot web routes produced complete protection to challenge. Goslings given vaccine via their drinking water were not resistant to challenge. The results suggest that the duck embryo adapted goose parvovirus vaccine induces a good immune response in susceptible goslings. However, further work is necessary to investigate whether the vaccine retains its attenuation following gosling to gosling passage.