A class I lentogenic newcastle disease virus strain confers effective protection against the prevalent strains
BIOLOGICALS
Authors: Li, Shu-yun; You, Guo-jin; Du, Ji-teng; Xia, Jing; Wen, Yi-ping; Huang, Xiao-bo; Zhao, Qing; Han, Xin-feng; Yan, Qi-gui; Wu, Rui; Cao, San-jie; Huang, Yong
Abstract
The traditional vaccine strains, such as LaSota, do not completely prevent the shedding of NDV. An ideal vaccine which could not only prevent the clinical signs, but significantly reduce the shedding of NDV is urgently needed for the eradication of ND. In this study, an NDV isolate APMV-1/Chicken/China (SC)/PT3/2016 (hereafter referred as PT3) was identified as a class I NDV and a lentogenic strain. The antigenic relationship between PT3 and 3 other NDV strains, including vaccine strain LaSota and 2 prevalent genotype VIId and VIb strains were analyzed. The protective efficacy of PT3 and LaSota against challenge with genotype VIId and VIb strains were assessed. The antigenic analysis result showed that 4 strains belong to the single serotype and the PT3 antiserum exhibited the highest HI titer against 3 other NDV strains. The results of protective efficacy showed that both of LaSota and PT3 could provide 100% survivability for infected chickens. However, PT3 performed better in inducing higher humoral responses and reducing virus shedding than the LaSota strain. Lentogenic strains from Class I NDV appear to be promising vaccine candidates for the control of ND, and allows for the easy discrimination of field NDV and vaccine strains.
Awareness and antibody detection of Newcastle disease virus in a neglected society in Nigeria
VETERINARY WORLD
Authors: Daodu, Oluwafemi Babatunde; Aiyedun, Julius Olaniyi; Kadir, Rafiu Adebisi; Ambali, Hauwa Motunrayo; Oludairo, Oladapo Oyedeji; Olorunshola, Isaac Dayo; Daodu, Oluwakemi Christiana; Baba, Saka Saheed
Abstract
Aim: This study aimed to assess the level of awareness of rural poultry farmers on vaccination and to detect Newcastle disease virus (NDV) antibody in local birds (LB) and eggs in Kwara State, Nigeria. Materials and Methods: Data on farmers' attitude, knowledge, practices, and experiences on ND mortality were obtained through an interview using a structured cross-sectional checklist. NDV antibodies were detected in sera and egg yolks of local chickens (LC) and guinea fowls (GF) using hemagglutination inhibition test. Results: A total of 83 interviewees, 287 sera and 121 egg yolk extracts, were examined. The study revealed that 98.8% (82/83) of the interviewee had never vaccinated their flock before. 90% of the interviewee had reported high mortality in birds within 1-6 months old, while the major clinical signs were cold (40.4%) and torticollis (30.8%). Evidences of LB exposure to wild-type NDV were confirmed by the detection of NDV antibodies in 20.8% and 0% of LC and GF, respectively. The mortality differences experienced in <1 and 1-6 months old LB could be explained by the presence of maternally-derived NDV antibody (49.6%) in egg yolk. Conclusion: The study showed that LB suffers from NDV as a result of LB keepers' ignorance and neglect by the government. This has limited local investment and subsequent contribution to gross domestic product. This study suggests that the key factors to the prevention of ND remain awareness creation about poultry vaccination, production of affordable vaccines, and availability/accessibility to veterinarian (or trained personnel).