Miller Laura C, Anderson Sarah J, Buckley Alexandra C, Schirtzinger Erin E, Hasan Mahamudul, Sarlo Davila Kaitlyn M, Fleming Damarius S, Lager Kelly M, Li Jiuyi, Sang Yongming
Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, 1800 Denison Ave, Manhattan, KS 66506, USA.
Virus and Prion Research Unit, National Animal Disease Center, United States Department of Agriculture-Agricultural Research Service, 1920 Dayton Ave, Ames, IA 50010, USA.
Vaccines (Basel). 2025 Apr 15;13(4):413. doi: 10.3390/vaccines13040413.
: Porcine reproductive and respiratory syndrome virus (PRRSV) significantly impedes swine production due to rapid genetic variation and suppression of antiviral interferon (IFN) responses, leading to ineffective immunity. To address this, we developed IFNmix, a replication-competent PRRSV modified live vaccine (MLV) candidate co-expressing three Type I IFN subclasses (IFNα, IFNβ, IFNδ) to enhance antiviral immunity. : In two independent in vivo experiments, we compared the protection of IFNmix and a commercial PRRSV MLV vaccine during challenge with a virulent PRRSV strain. Clinical signs, antibody and cytokine production, viral replication, and lung pathology in IFNmix-vaccinated pigs were compared to those of commercial PRRSV vaccines and controls. : Pigs vaccinated with IFNmix exhibited similar anti-PRRSV antibody development, serum viral loads, lung lesions, and cytokine responses post-challenge with the virulent NADC34 strain, with comparable or lower body temperatures and weight gain, to pigs vaccinated with the commercial vaccines. While IFNmix showed early viral load reduction compared to the commercial vaccine (Days 7-14 post-challenge), it demonstrated similar efficacy in controlling PRRSV replication and lung pathology. These findings suggest that IFNmix, by expressing multiple IFNs, can potentially enhance innate and adaptive immune responses, offering a promising approach to improving PRRSV vaccine efficacy. Further studies are needed to evaluate IFNmix against a broader range of PRRSV strains and to optimize its attenuation and immunogenicity.
猪繁殖与呼吸综合征病毒（PRRSV）由于其快速的基因变异以及对抗病毒干扰素（IFN）反应的抑制，严重阻碍了养猪业的发展，导致免疫无效。为了解决这一问题，我们开发了IFNmix，这是一种有复制能力的PRRSV修饰活疫苗（MLV）候选疫苗，共表达三种I型干扰素亚类（IFNα、IFNβ、IFNδ）以增强抗病毒免疫力。
在两项独立的体内实验中，我们比较了IFNmix和一种商业PRRSV MLV疫苗在受到强毒PRRSV毒株攻击时的保护效果。将接种IFNmix疫苗的猪的临床症状、抗体和细胞因子产生、病毒复制以及肺部病理情况与接种商业PRRSV疫苗的猪和对照组进行了比较。
接种IFNmix疫苗的猪在受到强毒NADC34毒株攻击后，其抗PRRSV抗体产生、血清病毒载量、肺部病变和细胞因子反应与接种商业疫苗的猪相似，体温和体重增加相当或更低。虽然与商业疫苗相比，IFNmix在攻击后早期（第7 - 14天）病毒载量有所降低，但在控制PRRSV复制和肺部病理方面显示出相似的效果。这些发现表明，IFNmix通过表达多种干扰素，有可能增强先天性和适应性免疫反应，为提高PRRSV疫苗效力提供了一种有前景的方法。需要进一步研究以评估IFNmix对更广泛的PRRSV毒株的效果，并优化其减毒和免疫原性。
