An Ulster 2C strain‐derived Newcastle disease vaccine: Efficacy and excretion in maternally immune chickens

Abstract

Efficacy and excretion of an Ulster strain-derived Newcastle disease (ND) vaccine (Poulvac NDW Broiler) were examined in maternally immune chickens. The vaccine was effective in broilers following coarse spray or aerosol (Atomist) application at one to 10 days of age. Immunity did not differ significantly from immunity following vaccination with a La Sota type vaccine. Also, combined spray application of NDW- and infectious bronchitis (IB) (Poulvac IB primer) vaccine at 1-day-old, resulted in sufficient protection against challenge with both virulent ND and IB virus. In layers the vaccine was less immunogenic, requiring large doses to induce sufficient protection in chickens with maternal antibodies. In layers this may make the vaccine economically non-viable. Atomist vaccination using economically justified doses, was effective after maternal antibodies had waned. Clinical signs of vaccinal reaction were not observed in layers. In broilers respiratory signs of vaccinal reaction were absent after spray-application and were very slight following Atomist administration. Body weight gain was temporarily depressed, but significantly less than following vaccination with a La Sota type vaccine. Following vaccination, vaccine virus could be recovered from cloacal content and trachea up to 15 and 8 days respectively.

An Ulster 2C strain‐derived Newcastle disease vaccine: Vaccinal reaction in comparison with other lentogenic Newcastle disease vaccines

“…NDW vaccine had no effect on body weight gain of SPF-WL chickens but induced growth retardation in maternally immune broilers, although significantly less than Clone 30 vaccine (P<0.001). Growth depression, which showed to be temporary, was also observed in broilers following sprayapplication (Van Eck et al, 1991 in order of magnitude of 1,000 EIE> 50 . This virus dose provoked an excellent seroresponse in SPF-WL chicks exposed to aerosols of NDP-, LZ58-, and Clone 30 vaccine.…”

“…In layers the vaccine was less immunogenic, requiring economically non-viable, large doses to induce sufficient protection in chickens with maternal antibodies. However, vaccination with economically justified doses, was effective after maternal antibodies had waned (Van Eck et al, 1991). Allan & Borland (1979) determined stress indices of a number of ND vaccines based on respiratory and general distress and mortality in one-week old chicks following controlled aerosol exposure.…”

Comparative Studies on the Oral and Intraocular Routes of Administration of Newcastle Disease Vaccine, La Sota in Adult Chickens.

“…Various factors have been noted to affect the antibody production or responses in chickens, prominent among them are route of vaccine administration and the age of the chicken at vaccination [13,14]. This study compared the intraocular and oral routes of administration of ND vaccine La Sota in grown or adult chickens.…”

Simple Differentiation of Avirulent and Virulent Strains of Avian Paramyxovirus Serotype-1 (Newcastle Disease Virus) by PCR and Restriction Endonuclease Analysis in Japan

“…Furthermore, most flocks are now given commercial ND live vaccines, and the vaccinated virus is sometimes re-isolated after administration [14]. In such cases, the PCR-REA method described in this study will be useful for discriminating vaccine strains from field viruses.…”