Thermoresistant Newcastle disease vaccine effectively protects SPF, native, and commercial chickens in challenge with virulent virus

Abstract

Background Due to the more stability and a better homogenecity in immune response, the use of thermoresistant vaccines in different chicken types has been increased. Objective This study aimed to evaluate the efficacy of a newly developed Newcastle disease vaccine (ND.TR.IR) originating from I‐2 strain in specific pathogen‐free (SPF) and native and broiler chickens. Methods Following determination of pathogenicity indices on the candidate seed, three efficacy examinations were conducted. In the first experiment, 120 1‐day‐old SPF chickens were randomly allocated to six groups and either vaccinated with ND.TR.IR via eye drop at 1, 7, and 21 days of age (V1, V7, and V21), or considered as non‐vaccinated control groups (C1, C7, and C21). At 20th post‐vaccination day, sera hemagglutination inhibition (HI) antibody titres against ND virus (NDV) were measured and then the chickens were challenged by virulent NDV (vNDV). In the second and third experiments, the efficacy of ND.TR.IR vaccine was compared to routine vaccination program (B1 and LaSota) in native and broiler chickens that were vaccinated at 10 and 20 days of age, respectively. The HI antibody titres were measured on 10, 20, 30, and 40 days of age, and also challenge efficacy test with vNDV was conducted on 30 days of age. Results The studied virus, as a vaccinal seed, complied with the pathogenicity indices of avirulent NDV and molecular identity of I‐2 strain. In the efficacy evaluation trials, the vaccinated chickens had higher HI antibody titres against NDV compared with their corresponding control chickens (p < 0.05). Results of the challenge tests indicated 95% and 100% protection against vNDV in native, SPF, and broiler‐vaccinated chickens, respectively. Conclusions The present findings indicated that administration of ND.TR.IR induced appropriate HI antibody titres against NDV in SPF, native, and broiler chickens associated with good protection in efficacy test.

Evaluation of the Newcastle disease virus genotype VII–mismatched vaccines in SPF chickens: A challenge efficacy study

“…Some studies, however, have reported the effectiveness of combined inactivated genotype II (La Sota) and genotype VII vaccines in reducing virus shedding ( Mahmoud et al, 2019 ). Previous investigations have shown that inoculation with the ND.TR.IR vaccine, a live genotype I-based strain, conferred satisfactory protection against local genotype VII virulent NDV and the Herts 33 strain ( Abdoshah et al, 2022 ; Hassanzadeh et al, 2023 ).…”

Superior Efficacy of Apathogenic Genotype I (V4) over Lentogenic Genotype II (LaSota) Live Vaccines against Newcastle Disease Virus Genotype VII.1.1 in Pathogen-Associated Molecular Pattern-H9N2 Vaccinated Broiler Chickens

“…Antigenic similarity between the circulating velogenic (vNDV) and the vaccine strain could improve the induced vaccinal protection in terms of reduced infectivity and virus shedding [6,[17][18][19]. Vaccination with a live genotype I-based vaccine (ND.TR.IR strain) has protected broiler chickens against the local heterologous genotype VII vNDV and Herts 33 strain in Iran [20,21].…”

Histopathological Alteration and Protein Markers Expression in Vaccinated Broilers Supplemented With Saccharomyces cerevisiae and Probiotic

“…The immunity system to disease depends on the existence of a complex of a highly sophisticated and inner immunity system called lymphatic system. Newcastle disease belongs to paramyxoviridae family [1], represented a serious peril on backyard chicken and poultry industry over the world and the spread of this illness may lead to severe trade restrictions on poultry products [2]. Histopathological changes following Newcastle disease virus infection includes infiltration of inflammatory cell, depletion of the lymphoid organs, degeneration and necrosis and the severity of these changes vary according to the strain, health condition of the host, immunity status and dose of the virus.…”