Karami S, Karimi V, Barin A, Rouigari M R, Bozorgmehri Fard M H
Department of Poultry Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Department of Microbiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Arch Razi Inst. 2024 Jun 30;79(3):499-506. doi: 10.32592/ARI.2024.79.3.499. eCollection 2024 Jun.
Highly pathogenic avian influenza (HPAI) is a viral disease caused by some H5 and H7 subtypes of influenza virus type A in most species of birds, especially poultry. HPAI viruses are among the most challenging viruses that threaten both human and animal health. Consequently, various strategies, such as the use of vaccines have been proposed to control the disease. After a catastrophic pandemic and the failure of conventional methods (elimination and extermination) in Iran, multiple vaccines have been used to control the disease. This study investigates the immunogenicity of two recombinant inactivated commercial vaccines of H5N1 and H5N3 subtypes in laying pullet flocks in Tehran Province, Iran. From 32 halls in six breeding units of laying pullets, 3,200 sera, and 800 tracheal and cloacal swabs were collected. After collecting the samples, Serum neutralisation (SN) and hemagglutination inhibition (HI) tests were conducted on sera to determine the serum titers of H5 specific antibody obtained from vaccine inoculation in three steps: before, after the first vaccination, and after the second vaccination (booster). The SN and HI tests were carried out by the alpha and beta methods on the pooled samples by the vaccine type (as antigen for HI and SN), and the results were compared. The PCR was performed on the tracheal and cloacal swab samples to possibly detect the HA (H5) virus in the studied flocks. The HI test results showed that both vaccines had a Serum antibody titre above 5 (log) after two vaccination rounds, indicating a desirable immunogenic response. The SN test results also showed a neutralisation index above 10 for both vaccines, indicating more than 50% reduction in antigenicity of the virus. The PCR results were negative. This study was the first investigation of immunogenicity following two-time vaccination against H5 subtype vaccines in Iranian poultry flocks, indicating suitable antibody titer against the influenza virus in vaccinated flocks.
高致病性禽流感（HPAI）是一种由甲型流感病毒的某些H5和H7亚型引起的病毒性疾病，可感染大多数鸟类，尤其是家禽。高致病性禽流感病毒是威胁人类和动物健康的最具挑战性的病毒之一。因此，人们提出了各种策略，如使用疫苗来控制这种疾病。在伊朗经历了一场灾难性的大流行且传统方法（扑杀和消灭）失败后，人们使用了多种疫苗来控制该疾病。本研究调查了两种H5N1和H5N3亚型重组灭活商业疫苗在伊朗德黑兰省产蛋小母鸡群中的免疫原性。从六个产蛋小母鸡育种单位的32个鸡舍中，采集了3200份血清以及800份气管和泄殖腔拭子。采集样本后，对血清进行了血清中和（SN）和血凝抑制（HI）试验，以确定在三个阶段（首次接种前、首次接种后和第二次接种（加强）后）从疫苗接种中获得的H5特异性抗体的血清滴度。SN和HI试验分别采用α法和β法，以疫苗类型为分组依据（作为HI和SN的抗原）对混合样本进行检测，并对结果进行比较。对气管和泄殖腔拭子样本进行PCR检测，以可能检测所研究鸡群中的HA（H5）病毒。HI试验结果表明，两种疫苗在两轮接种后血清抗体滴度均高于5（对数），表明免疫原性反应良好。SN试验结果还表明，两种疫苗的中和指数均高于10，表明病毒抗原性降低了50%以上。PCR结果为阴性。本研究是对伊朗家禽群两次接种H5亚型疫苗后免疫原性的首次调查，表明接种疫苗的鸡群对流感病毒具有合适的抗体滴度。
