Wu Yu, Lin Limiao, Gao Xiaopeng, Zheng Jiaying, Yin Lijuan, Zhao Haishen, Ren Bohua, Wang Lianxiang, Li Qunhui
Wen's Food Group, Yunfu, China.
State Key Laboratory of Biocontrol, Guangzhou Higher Education Mega Center, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.
Front Vet Sci. 2024 Nov 20;11:1472960. doi: 10.3389/fvets.2024.1472960. eCollection 2024.
In recent years, NADC34-like strains of porcine reproductive and respiratory syndrome virus have gradually emerged as mainstream strains on Chinese pig farms. These strains have high mutation rates and can recombine with local strains, representing great challenges to prevention and control efforts. Previously, a new recombinant NADC34-like subtype strain was isolated in our laboratory. Herein, we evaluated the cross-protective effect of the VR2332 modified live virus (MLV) against the novel NADC34-like recombinant strain using the immune challenge protection test in piglets and sows. The results revealed that immunization with the vaccine in piglets significantly reduced viremia, lung damage and stimulated the production of PRRSV-N antibodies. In the sow challenge experiment, one abortion and one death were recorded in the positive control group, and the survival rate of offspring was only 25%. However, there were no sow deaths or abortions in the immunization group during the experiment, and the average piglet survival rate was high at 76.5%. In general, the VR2332 MLV confers a certain extent of cross-protection against the NADC34-like recombinant strain, providing an effective reference and guidance for prevention and control efforts and clinical vaccine use.
近年来，猪繁殖与呼吸综合征病毒（PRRSV）的NADC34样毒株逐渐成为中国猪场的主流毒株。这些毒株突变率高，且能与本地毒株发生重组，给防控工作带来巨大挑战。此前，本实验室分离出一株新型重组NADC34样亚型毒株。在此，我们通过仔猪和母猪免疫攻毒保护试验，评估了VR2332活疫苗（MLV）对新型NADC34样重组毒株的交叉保护效果。结果显示，仔猪接种该疫苗后，病毒血症和肺损伤显著减轻，并刺激了PRRSV-N抗体的产生。在母猪攻毒试验中，阳性对照组记录到1例流产和1例死亡，后代存活率仅为25%。然而，免疫组在试验期间未出现母猪死亡或流产情况，仔猪平均存活率较高，为76.5%。总体而言，VR2332 MLV对NADC34样重组毒株具有一定程度的交叉保护作用，为防控工作及临床疫苗使用提供了有效的参考和指导。
