Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
BioApplications Inc., Pohang Techno Park Complex, Pohang, Republic of Korea.
Vet Med Sci. 2023 Nov;9(6):2703-2710. doi: 10.1002/vms3.1256. Epub 2023 Sep 4.
The objective of this field trial was to evaluate the efficacy of a new plant-based porcine circovirus type 2a (PCV2a) vaccine. This vaccine was a recombinant capsid subunit PCV2a vaccine based on the Nicotiana benthamiana expression system.
Three farms were selected for the study based on their history of subclinical PCV2 infection. A total of 40 18-day-old pigs were randomly allocated to either vaccinated or unvaccinated groups (20 pigs per group; 10 = male and 10 = female). Pigs received a 2.0-mL dose of the plant-based PCV2a vaccine intramuscularly at 21 days of age in accordance with the manufacturer's recommendations, whereas unvaccinated pigs were administered a single dose of phosphate buffered-saline at the same age.
Vaccination had a positive effect on pig growth performance compared to that of unvaccinated pigs on all three of the farms. Vaccination of pigs with a plant-based PCV2a vaccine induced high levels of neutralizing antibodies titres against PCV2d and PCV2d-specific interferon-γ secreting cells which resulted in the reduction of PCV2d viral load and reduced lymphoid lesions severity.
The results of this field trial demonstrated cross-protection of PCV2d by a plant-based PCV2a vaccine and a positive effect of pig growth performance with vaccination.
本田间试验的目的是评估一种新型植物源性猪圆环病毒 2 型（PCV2a）疫苗的效力。该疫苗是一种基于 Nicotiana benthamiana 表达系统的重组衣壳亚单位 PCV2a 疫苗。
根据亚临床 PCV2 感染史，选择了三个农场进行研究。将 40 头 18 日龄仔猪随机分为疫苗组和未接种组（每组 20 头；10 头♂，10 头♀）。按照制造商的建议，21 日龄时，猪肌肉内注射 2.0 毫升剂量的植物源性 PCV2a 疫苗，而未接种疫苗的猪在相同年龄时给予单次剂量的磷酸盐缓冲盐水。
与未接种疫苗的猪相比，疫苗接种对所有三个农场的猪生长性能均有积极影响。接种植物源性 PCV2a 疫苗可诱导针对 PCV2d 的高水平中和抗体滴度和 PCV2d 特异性干扰素-γ分泌细胞，从而降低 PCV2d 病毒载量并减轻淋巴样病变的严重程度。
田间试验结果表明，植物源性 PCV2a 疫苗可对 PCV2d 产生交叉保护作用，并对猪生长性能产生积极影响。
