Winterfield R W, Dhillon A S, Alby L J
Poult Sci. 1980 Feb;59(2):240-6. doi: 10.3382/ps.0590240.
Chickens were vaccinated and revaccinated with inactivated Newcastle disease (ND) vaccines from 2 different sources and also with LaSota strain, live Newcastle disease virus (NDV). Both inactivated vaccines induced higher virus neutralizing (VN) and hemagglutination-inhibition (HI) titers than the LaSota virus. One of the inactivated preparations was found superior to the other by both the VN and HI tests. However, poor protection from apparent virus replication, virus shed, and transmission occurred after challenge with a velogenic NDV strain in those vaccinated with each of the inactivated vaccines. In contrast, LaSota virus, given by the eye drop route, produced excellent protection by the same criteria. In one of the groups of chickens, gross lesions of airsacculitis were seen after vaccination with an inactivated vaccine and subsequent challenge. Revaccination with inactivated vaccines did not enhance the protection of the respiratory tract but did result in an anamnestic serological response (VN and HI). In the post-challenge period, the use of tracheal swabs proved more sensitive as an indicator of virus shed than did cloacal swabs with the velogenic NDV strain used. The practical implications of observations made from the trials are discussed.
用来自2种不同来源的灭活新城疫（ND）疫苗以及新城疫病毒（NDV）LaSota活毒株对鸡进行免疫接种和再免疫接种。两种灭活疫苗诱导产生的病毒中和（VN）和血凝抑制（HI）效价均高于LaSota病毒。通过VN和HI试验发现，其中一种灭活制剂优于另一种。然而，在用强毒株新城疫病毒攻击后，接种每种灭活疫苗的鸡在明显的病毒复制、病毒排出和传播方面的保护效果较差。相比之下，通过滴眼途径接种的LaSota病毒，按照相同标准产生了优异的保护效果。在一组鸡中，接种灭活疫苗并随后进行攻击后出现了气囊炎的肉眼病变。用灭活疫苗进行再免疫接种并未增强呼吸道的保护作用，但确实引发了回忆性血清学反应（VN和HI）。在攻毒后阶段，对于所使用的强毒株新城疫病毒，气管拭子作为病毒排出指标比泄殖腔拭子更敏感。讨论了从试验中得出的观察结果的实际意义。
