Borca Manuel V, Ramirez-Medina Elizabeth, Mutisya Christine, Ojuok Rose, Odaba Josiah, Dihbol Mark, Lacasta Anna, Gladue Douglas P
Plum Island Animal Disease Center, Agricultural Research Service, USDA, Greenport, NY 11944, USA.
National Bio and Agro-Defense Facility, Agricultural Research Service, USDA, Manhattan, KS 66506, USA.
Vaccines (Basel). 2025 Aug 13;13(8):858. doi: 10.3390/vaccines13080858.
Vaccine development for the prevention of ASF has been very challenging due to the extensive genetic and largely unknown antigenic diversity. Inactivated vaccines, using different inactivation methods and a variety of adjuvants, have been consistently inefficacious. Historically, animals recovering from an infection with an attenuated virus became protected from the development of a clinical disease caused by an antigenically related strain. Therefore, immunization of susceptible animals with attenuathe ted virus strains has become a common method of vaccination with the first two commercially available vaccines based on recombinant live-attenuated viruses (LAVs). An important limitation is that the efficacy of the LAV is restricted to those strains that are antigenically related and, in most cases, only provide protection against homologous strains. Due to the unknown antigenic heterogeneity among all ASFV field isolates, the development of broad-spectrum vaccines is a challenge. Besides the anecdotal data, there is not a large amount of information describing patterns of cross-protection between different ASFV strains. We evaluated the cross-protection induced by the ASFV live-attenuated vaccine ASFV-G-ΔI177L against different biotypes of ASFV and compared their genomic sequences to determine potential genetic mutations that could cause the lack of cross-protection. Results presented here demonstrate different patterns of protection when ASFV-G-ΔI177L vaccinated pigs were challenged with six different ASFV field isolates belonging to different biotypes. The presence of cross-protection cannot be predicted solely by the classical methodology for genotyping-based B646L ORF only. Biotyping, considering the entire virus proteome, appears to be a more promising prediction tool, although additional gathering of experimental data will be necessary to fully validate it; until then, the presence of cross-protection needs to be confirmed in efficacy trials challenging vaccinated animals.
由于非洲猪瘟病毒（ASF）存在广泛的基因差异且其抗原多样性很大程度上未知，因此开发预防ASF的疫苗极具挑战性。使用不同灭活方法和多种佐剂的灭活疫苗一直都没有效果。从历史上看，感染减毒病毒后康复的动物对由抗原相关毒株引起的临床疾病具有抵抗力。因此，用减毒病毒株对易感动物进行免疫接种已成为一种常见的疫苗接种方法，前两种市售疫苗就是基于重组活减毒病毒（LAV）。一个重要的局限性是，LAV的效力仅限于那些抗原相关的毒株，而且在大多数情况下，仅能提供针对同源毒株的保护。由于所有ASF病毒野毒株之间的抗原异质性未知，开发广谱疫苗是一项挑战。除了一些传闻数据外，没有大量信息描述不同ASF病毒株之间的交叉保护模式。我们评估了ASF活减毒疫苗ASFV-G-ΔI177L对不同生物型ASF病毒诱导的交叉保护作用，并比较了它们的基因组序列，以确定可能导致缺乏交叉保护的潜在基因突变。此处给出的结果表明，用ASFV-G-ΔI177L接种的猪在用六种属于不同生物型的不同ASF病毒野毒株攻击时，呈现出不同的保护模式。不能仅通过基于B646L开放阅读框的经典基因分型方法来预测交叉保护的存在。考虑到整个病毒蛋白质组的生物分型似乎是一种更有前景的预测工具，不过还需要收集更多实验数据才能充分验证它；在此之前，需要在对接种疫苗动物进行攻击的效力试验中确认交叉保护的存在。
