title: A study on the long-term immunity induced by La Sota strain of Newcastle disease virus grown in a BS/BEK cell line of bovine embryo kidney origin.
abstract: Twenty-day-old susceptible chickens were divided into three groups; two were vaccinated with inactivated, water in oil emulsified La Sota strain of Newcastle disease virus (NDV) obtained from a bovine embryo kidney (BS/BEK) cell line and from chicken embryos, respectively. The third unvaccinated group represented the control. At 30-day intervals subgroups were exposed to the Herts 33 virulent NDV strain. Serological and clinical findings showed no appreciable difference in the immunogenicity of the antigen from either culture systems and no significant differences could be observed in its ability to protect against ND challenge.
authors.affiliation: Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia, Brescia, Italy.
authors.forename: M N
authors.initials: MN
authors.lastname: Losio
authors.forename: E
authors.initials: E
authors.lastname: Lodetti
authors.forename: L
authors.initials: L
authors.lastname: Alborali
authors.forename: G
authors.initials: G
authors.lastname: Tosi
authors.forename: C
authors.initials: C
authors.lastname: Buonavoglia