Coronado Liani, Cobos Àlex, Muñoz-Aguilera Adriana, Puente-Marin Sara, Guevara Gemma, Riquelme Cristina, Heredia Saray, Borca Manuel V, Ganges Llilianne
WOAH Reference Laboratory for Classical Swine Fever, IRTA-CReSA, 08193 Barcelona, Spain.
Unitat Mixta d'Investigació IRTA-UAB en Sanitat Animal, Centre de Recerca en Sanitat Animal (CReSA), Bellaterra, 08193 Barcelona, Spain.
Vaccines (Basel). 2025 Jul 28;13(8):803. doi: 10.3390/vaccines13080803.
BACKGROUND/OBJECTIVES: Classical swine fever (CSF) continues to challenge global eradication efforts, particularly in endemic regions, where pregnant sows face heightened risks of vertical transmission following exposure to CSFV.
This study evaluates the early protective efficacy of FlagT4G, a novel live attenuated DIVA-compatible vaccine. Pregnant sows were vaccinated at mid-gestation and challenged 14 days later with a highly virulent CSFV strain.
FlagT4G conferred complete clinical protection, preventing both maternal viremia and transplacental transmission. No CSFV RNA, specific antibodies, or IFN-α were detected in fetal samples from vaccinated animals. In contrast, unvaccinated sows exhibited clinical signs, high viral loads, and widespread fetal infection. Interestingly, early protection was observed even in the absence of strong humoral responses in some vaccinated sows, suggesting a potential role for innate or T-cell-mediated immunity in conferring rapid protection.
The demonstrated efficacy of FlagT4G within two weeks of vaccination underscores its feasibility for integration into emergency vaccination programs. Its DIVA compatibility and ability to induce early fetal protection against highly virulent CSFV strains position it as a promising tool for CSF control and eradication strategies.
背景/目的：经典猪瘟（CSF）持续对全球根除工作构成挑战，尤其是在流行地区，怀孕母猪在接触猪瘟病毒（CSFV）后面临垂直传播风险增加的情况。
本研究评估了一种新型的与鉴别诊断疫苗兼容的减毒活疫苗FlagT4G的早期保护效果。怀孕母猪在妊娠中期接种疫苗，并在14天后用高致病性CSFV毒株进行攻毒。
FlagT4G提供了完全的临床保护，防止了母体病毒血症和经胎盘传播。在接种疫苗动物的胎儿样本中未检测到CSFV RNA、特异性抗体或IFN-α。相比之下，未接种疫苗的母猪表现出临床症状、高病毒载量和广泛的胎儿感染。有趣的是，即使在一些接种疫苗的母猪中没有强烈的体液反应，也观察到了早期保护，这表明先天免疫或T细胞介导的免疫在提供快速保护方面可能发挥作用。
FlagT4G在接种疫苗两周内所显示的效果强调了其纳入紧急疫苗接种计划的可行性。其与鉴别诊断疫苗的兼容性以及诱导早期胎儿免受高致病性CSFV毒株感染的能力使其成为猪瘟控制和根除策略的一个有前途的工具。
