Porcine parvovirus (PPV) is a major cause of the syndrome of sow reproductive failure that can cause economic losses. In this study, we developed a subunit vaccine against porcine parvovirus (PPV), composed of virus-like particles (VLPs) derived from a prokaryotic system, and evaluated its potential against PPV infection. The soluble recombinant VP2 protein was expressed in E. coli Transetta(DE3) cells using a pCold II prokaryotic expression vector at a low temperature of 15 °C. After expression and purification, the recombinant VP2 protein was successfully assembled into VLPs with a similar shape of PPV viron and also hemagglutination activity. PPV VLPs formulated in a water-in-oil-in-water adjuvant evoked high hemagglutination inhibition antibody and neutralization antibody titres in both guinea pigs, used as reference model, and target species, pigs. Immunization with VLPs vaccine stimulated high hemagglutination inhibition antibody and neutralization antibody responses in guinea pigs, used as reference, and target species, weaned pigs, and primiparous gilts. PPV VLPs from E. coli yielded complete fetal protection against PPV infection in primiparous gilts immunized with a single-dose vaccine. PPV VLPs inhibited the replication and spread of PPV in primiparous gilts, which was confirmed by the detection of PPV DNA and infectious PPV in nasal and rectal swabs of challenged sows. These results suggest that VLPs-based PPV vaccine is a promising PPV vaccine candidate.

猪细小病毒（PPV）是造成母猪生殖衰竭综合症的主要原因，可导致经济损失。在这项研究中，我们开发了一种针对猪细小病毒（PPV）的亚单位疫苗，该疫苗由原核系统衍生的病毒样颗粒（VLP）组成，并评估了其对PPV感染的潜力。可溶性重组VP2蛋白在大肠杆菌中表达使用pCold II原核表达载体在15°C的低温下转染Transetta（DE3）细胞。表达和纯化后，重组VP2蛋白成功组装成具有类似PPV病毒体形状和血凝活性的VLP。用水包油包水佐剂配制的PPV VLP在用作参考模型的豚鼠和目标物种的猪中引起高血凝抑制抗体和中和抗体的效价。VLPs疫苗免疫后，在作为参考的豚鼠和目标物种，断奶猪和初生小母猪中刺激了高血凝抑制抗体和中和抗体的反应。大肠杆菌的PPV VLP在用单剂量疫苗免疫的初生后备母猪上获得了针对PPV感染的完整胎儿保护。PPV VLPs抑制了PPV在初生小母猪中的复制和扩散，这通过检测母猪的鼻和直肠拭子中的PPV DNA和感染性PPV得以证实。这些结果表明基于VLP的PPV疫苗是有前途的PPV疫苗候选者。