title: Attenuation of infectious bursal disease virus and vaccination trials under laboratory and field conditions.
abstract: Adaptation to the chicken embryo of a virus strain of infectious bursal disease resulted in a reduction in virulence. After 60 passages the strain was attenuated enough to be used as a vaccine. The attenuation proved adequately stable. If given orally in the drinking water, the strain induced the development of neutralising and precipiting antibodies and a strong resistance against the disease. Promising results have also been obtained in the field.
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia a dell'Emilia, BRESCIA, Italia.
authors.forename: A
authors.initials: A
authors.lastname: Rinaldi
authors.forename: D
authors.initials: D
authors.lastname: Cessi
authors.forename: G
authors.initials: G
authors.lastname: Cervio
authors.forename: E
authors.initials: E
authors.lastname: Lodetti