Barboza-Solis Catalina, Najimudeen Shahnas M, Perez-Contreras Ana, Ali Ahmed, Joseph Tomy, King Robin, Ravi Madhu, Peters Delores, Fonseca Kevin, Gagnon Carl A, van der Meer Frank, Abdul-Careem Mohamed Faizal
Health Research Innovation Center 2C53, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada.
Department of Pathology, Beni-Suef University, Beni Suef 62511, Egypt.
Vaccines (Basel). 2021 Dec 3;9(12):1425. doi: 10.3390/vaccines9121425.
In Alberta, infectious laryngotracheitis virus (ILTV) infection is endemic in backyard poultry flocks; however, outbreaks are only sporadically observed in commercial flocks. In addition to ILTV vaccine revertant strains, wild-type strains are among the most common causes of infectious laryngotracheitis (ILT). Given the surge in live attenuated vaccine-related outbreaks, the goal of this study was to assess the efficacy of a recombinant herpesvirus of turkey (rHVT-LT) vaccine against a genotype VI Canadian wild-type ILTV infection. One-day-old specific pathogen-free (SPF) White Leghorn chickens were vaccinated with the rHVT-LT vaccine or mock vaccinated. At three weeks of age, half of the vaccinated and the mock-vaccinated animals were challenged. Throughout the experiment, weights were recorded, and feather tips, cloacal and oropharyngeal swabs were collected for ILTV genome quantification. Blood was collected to isolate peripheral blood mononuclear cells (PBMC) and quantify CD4+ and CD8+ T cells. At 14 dpi, the chickens were euthanized, and respiratory tissues were collected to quantify genome loads and histological examination. Results showed that the vaccine failed to decrease the clinical signs at 6 days post-infection. However, it was able to significantly reduce ILTV shedding through the oropharyngeal route. Overall, rHVT-LT produced a partial protection against genotype VI ILTV infection.
在艾伯塔省，传染性喉气管炎病毒（ILTV）感染在家养禽群中呈地方性流行；然而，商业禽群中仅偶尔观察到疫情暴发。除了ILTV疫苗回复株外，野生型毒株也是传染性喉气管炎（ILT）最常见的病因之一。鉴于减毒活疫苗相关疫情的激增，本研究的目的是评估重组火鸡疱疹病毒（rHVT-LT）疫苗对VI型加拿大野生型ILTV感染的效力。将1日龄无特定病原体（SPF）白来航鸡用rHVT-LT疫苗接种或进行假接种。在3周龄时，对接种疫苗和假接种的动物各一半进行攻毒。在整个实验过程中，记录体重，并采集羽毛尖端、泄殖腔和口咽拭子用于ILTV基因组定量。采集血液以分离外周血单核细胞（PBMC）并定量CD4+和CD8+T细胞。在感染后14天，对鸡实施安乐死，并采集呼吸组织以定量基因组载量并进行组织学检查。结果表明，该疫苗未能在感染后6天减轻临床症状。然而，它能够显著减少通过口咽途径的ILTV排毒。总体而言，rHVT-LT对VI型ILTV感染产生了部分保护作用。
