Red-spotted grouper nervous necrosis virus (RGNNV) is a highly infectious, explosive, and lethal virus that mainly infects marine fish larvae. Currently, there is no effective method to mitigate the impact of RGNNV on aquaculture production. Previous studies have shown that yolk immunoglobulin (IgY) can neutralize RGNNV in grouper fin-1 (GF-1) cells. In this study, RGNNV propagated in GF-1 cells was harvested and purified successfully. The purified RGNNV was used as an immunogen to immunize laying hens. Water-soluble fractions were separated from egg yolk, and IgY was harvested using a two-step precipitation method with saturated ammonium sulfate salt. In vitro analysis showed that the purified IgY could neutralize RGNNV. An in vivo protection assay with groupers revealed that fish fed with 10% lyophilized egg yolk powder from immunized hens were significantly protected during RGNNV challenge. The relative protection rates of groupers under treatment after RGNNV infection and continuous feeding during RGNNV infection were 68% and 70%, respectively, when fed with 10% specific egg yolk powder. This is the first study to validate that anti-RGNNV IgY can effectively protect groupers from RGNNV infection, laying a foundation for the development of anti-RGNNV products.

红斑石斑鱼神经坏死病毒（RGNNV）是一种传染性强、爆炸性强、致死率高的病毒，主要感染海鱼幼虫。目前，没有有效的方法来减轻 RGNNV 对水产养殖生产的影响。先前的研究表明，卵黄免疫球蛋白 (IgY) 可以中和石斑鱼 fin-1 (GF-1) 细胞中的 RGNNV。在这项研究中，在 GF-1 细胞中繁殖的 RGNNV 被成功收获和纯化。纯化的 RGNNV 用作免疫原来免疫蛋鸡。从蛋黄中分离出水溶性部分，并使用饱和硫酸铵盐的两步沉淀法收集 IgY。体外分析表明，纯化的 IgY 可以中和 RGNNV。一个在体内对石斑鱼的保护试验表明，在 RGNNV 攻击期间，用来自免疫母鸡的 10% 冻干蛋黄粉喂养的鱼受到显着保护。RGNNV感染后接受治疗的石斑鱼和RGNNV感染期间连续饲养的石斑鱼在饲喂10%的特定蛋黄粉时的相对保护率分别为68%和70%。这是首次验证抗RGNNV IgY可以有效保护石斑鱼免受RGNNV感染的研究，为开发抗RGNNV产品奠定了基础。