Ferreira Helena L, Miller Patti J, Suarez David L
Southeast Poultry Research Laboratory, US National Poultry Research Center, USDA-ARS, 934 College Station Rd., Athens, GA 30605, USA.
Department of Veterinary Medicine, FZEA-USP, University of Sao Paulo, Pirassununga, SP 13635-900, Brazil.
Vaccines (Basel). 2021 Feb 21;9(2):182. doi: 10.3390/vaccines9020182.
The efficacy of an adenovirus-vectored Newcastle disease virus (NDV) vaccine expressing the fusion (F) NDV protein (adeno-F) was evaluated against challenges with virulent heterologous and homologous NDV strains to the F protein. In a preliminary study, two different doses (low and high) of adeno-F were tested against a virulent NDV strain containing the homologous NDV F protein, CA02. In a second study, at three weeks post-vaccination, the efficacy of the high dose of adeno-F was compared to a live attenuated NDV vaccine strain (LaSota) against three antigenically distinct virulent NDV challenge strains, one homologous (CA02) and two heterologous (TZ12, EG14) to F in the vectored vaccine. In both experiments, clinical signs, mortality, virus shedding, and humoral response were evaluated. In the first experiment, the survival rates from birds vaccinated with adeno-F at a high and low dose were 100% and 25%, respectively. In the second experiment, birds vaccinated with the high dose of adeno-F had a survival rate of 80%, 75%, and 65% after challenge with the CA02, TZ12, and EG14 viruses, respectively. All of the LaSota-vaccinated birds survived post-challenge no matter the NDV challenge strain. High antibody titers were detected after vaccination with LaSota by HI and ELISA tests. The majority of adeno-F-vaccinated birds had detectable antibodies using the ELISA test, but not using the HI test, before the challenge. The data show that both the similarity of the F protein of the adeno-F vaccine to the challenge virus and the adeno-F vaccination dose affect the efficacy of an adenovirus-vectored NDV vaccine against a virulent NDV challenge.
对表达新城疫病毒（NDV）融合（F）蛋白的腺病毒载体新城疫病毒疫苗（腺病毒-F）针对具有异源和同源NDV毒株的F蛋白的攻毒进行了效力评估。在一项初步研究中，针对含有同源NDV F蛋白CA02的强毒NDV毒株测试了两种不同剂量（低剂量和高剂量）的腺病毒-F。在第二项研究中，在接种疫苗三周后，将高剂量腺病毒-F的效力与一种减毒活NDV疫苗株（LaSota）针对三种抗原性不同的强毒NDV攻毒株进行比较，其中一种与载体疫苗中的F同源（CA02），两种异源（TZ12、EG14）。在两个实验中，均评估了临床症状、死亡率、病毒排泄和体液反应。在第一个实验中，接种高剂量和低剂量腺病毒-F的鸡的存活率分别为100%和25%。在第二个实验中，接种高剂量腺病毒-F的鸡在分别用CA02、TZ12和EG14病毒攻毒后的存活率分别为80%、75%和65%。无论NDV攻毒株如何，所有接种LaSota疫苗的鸡在攻毒后均存活。通过血凝抑制（HI）和酶联免疫吸附测定（ELISA）测试在接种LaSota疫苗后检测到高抗体滴度。在攻毒前，大多数接种腺病毒-F的鸡使用ELISA测试可检测到抗体，但使用HI测试则检测不到。数据表明，腺病毒-F疫苗的F蛋白与攻毒病毒的相似性以及腺病毒-F的接种剂量均会影响腺病毒载体NDV疫苗针对强毒NDV攻毒的效力。
