Effects of the HN Antigenic Difference between the Vaccine Strain and the Challenge Strain of Newcastle Disease Virus on Virus Shedding and Transmission

Abstract

Newcastle disease (ND) leading to heavy economic losses to the poultry industry worldwide is caused by Newcastle disease virus (NDV). Even though intensive vaccination programs have been implemented in many countries, virulent NDV can still be frequently isolated in well-vaccinated flocks. We compared the protection efficiency of LaSota and two sub-genotype VIId vaccines, NDV/AI4 and NDV O/AI4, in which NDV O/AI4 was constructed by replacing the hemagglutinin–neuraminidase (HN) gene of the vaccine strain NDV/AI4 with that from the variant NDV strain JS-14-12-Ch by the cross hemagglutination inhibition test and immune protection test. The number of birds shedding the virus and the titer of the shedding virus from the challenged birds were tested to evaluate the protection efficiency in the immune protection test. The cross hemagglutination inhibition and neutralization tests between JS-14-12-Ch and the three vaccines displayed a significant antigenic difference between JS-14-12-Ch and LaSota or NDV/AI4, but not between JS-14-12-Ch and NDV O/AI4. The results of the immune protection test showed that NDV O/AI4 could provide improved protection as determined by a significant decrease in both the number of birds shedding the virus and the titer of the shedding virus from the challenged birds. The results in this study indicated that the antigenic similarity between the vaccine strain and the challenge strain is important in reducing the shedding of virulent virus in which the congruence of the NDV HN protein may play a critical role.

Positive selection pressure on E2 protein of classical swine fever virus drives variations in virulence, pathogenesis and antigenicity: Implication for epidemiological surveillance in endemic areas

“…The E2 protein of CSFV plays a relevant role in inducing immune protection against the viral infection and it is, therefore, prone to immune pressure to generate antigenic variation more easily (Hu et al, ; Perez, Diaz de Arce, et al, ; Rios et al, ; Shen et al, ; Tang et al, ). The combination of epitope and deimmunization classification, with antigenic characterization by cross‐neutralization and antigenic metric distance estimation, enables the development of antigenic maps for viral agents such as influenza virus (Li et al, ; Liu et al, ; Peng et al, ) or Newcastle disease virus (Liu et al, ). Indeed, this methodology has been successfully applied to establish early control measures for certain emergent strains of these viral agents, including changes to the type of vaccines to be used (Li et al, ; Liu et al, ).…”

“…The combination of epitope and deimmunization classification, with antigenic characterization by cross‐neutralization and antigenic metric distance estimation, enables the development of antigenic maps for viral agents such as influenza virus (Li et al, ; Liu et al, ; Peng et al, ) or Newcastle disease virus (Liu et al, ). Indeed, this methodology has been successfully applied to establish early control measures for certain emergent strains of these viral agents, including changes to the type of vaccines to be used (Li et al, ; Liu et al, ). To our knowledge, this is the first report applying the use of immunoinformatic approaches to characterize both T‐cell and B‐cell epitopes for the main immunogenic protein of CSFV (E2 protein), combining also cross‐neutralization and antigenic metric distance estimation for this viral agent.…”

“…The antigenic difference between two CSFV viral strains was measured using the Archetti‐Horsfall antigenic distance metric (1/ r ) (Archetti & Horsfall, ). Archetti‐Horsfall antigenic distance metric is independent of the viral receptor binding avidity of any two viruses (X and Y), it requires homologous and heterologous antibody titres for viruses X and Y and it has been widely accepted to classify antigenic differences among different viral agents including, influenza virus (Li et al, ), infectious canine hepatitis virus (Kinjo & Yanagawa, ), infectious bronchitis virus (Dolz, Pujols, Ordonez, Porta, & Majo, ) and others (Liu et al, ).…”

“…The antigenic distance metric for the CSFV strains was estimated using the following equation (1). Antigenic distances resulting 0.5 < (1/ r ) < 1.5 indicate no significant antigenic difference between the two viruses, results of 1.5 < (1/ r ) < 2 indicates antigenic difference between the two viruses, whereas (1/ r ) ≥ 2 means that the two virus strains present major antigenic difference (Archetti & Horsfall, ; Liu et al, ).…”

Presence of Newcastle Disease in Vaccinated Indigenous Chicken from Farms in Selected Regions in Kenya- a Cross Sectional Study

“…Therefore, the presence of the virus can be attributed to viral shedding. This can lead to subsequent transmission of the virus to susceptible flocks 11,13,24 .…”