Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Avda, Puerta de Hierro s/n, 28040 Madrid, Spain.
Vet Res. 2013 Dec 5;44(1):115. doi: 10.1186/1297-9716-44-115.
The objective of this study was to compare the safety of all modified live virus vaccines commercially available in Europe against Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) under the same experimental conditions. For this purpose, one hundred and twenty three-week-old piglets, divided into five groups, were used. On day 0 of the experiment, nine pigs per group were removed and the remaining fifteen were vaccinated with the commercial vaccines Ingelvac PRRS MLV, Amervac PRRS, Pyrsvac-183 and Porcilis PRRS by the IM route or were mock vaccinated and used as controls. On day 3, the nine unvaccinated pigs were re-introduced into their respective groups and served as sentinel pigs. Clinical signs were recorded daily and lung lesions were determined on days 7, 14 and 21, when 5 vaccinated pigs per group were euthanized. Blood samples and swabs were taken every three days and different organs were collected at necropsy to determine the presence of PRRSV. None of the vaccines studied caused detectable clinical signs in vaccinated pigs although lung lesions were found. Altogether, these results indicate that all vaccines can be considered clinically safe. However, some differences were found in virological parameters. Thus, neither Pyrsvac-183 nor Porcilis PRRS could be detected in porcine alveolar macrophage (PAM) cultures or in lung sections used to determine PRRSV by immunohistochemistry, indicating that these viruses might have lost their ability to replicate in PAM. This inability to replicate in PAM might be related to the lower transmission rate and the delay in the onset of viremia observed in these groups.
本研究的目的是在相同的实验条件下比较欧洲市售的所有经改良的活病毒疫苗在对抗猪繁殖与呼吸综合征病毒（PRRSV）时的安全性。为此，使用了 123 周龄的仔猪，分为五组。实验的第 0 天，每组中 9 头猪被移除，其余 15 头猪通过肌肉注射接种市售疫苗 Ingelvac PRRS MLV、Amervac PRRS、Pyrsvac-183 和 Porcilis PRRS，或作为对照进行模拟接种。第 3 天，将未接种的 9 头猪重新引入各自的组中，并作为哨兵猪。每天记录临床症状，在第 7、14 和 21 天，当每组有 5 头接种猪被安乐死时，测定肺部病变。每隔三天采集血样和拭子，并在剖检时收集不同的器官，以确定是否存在 PRRSV。研究中没有一种疫苗在接种猪中引起可检测到的临床症状，尽管发现了肺部病变。总的来说，这些结果表明所有疫苗都可以被认为是临床安全的。然而，在病毒学参数方面发现了一些差异。因此，Pyrsvac-183 和 Porcilis PRRS 都不能在猪肺泡巨噬细胞（PAM）培养物或用于通过免疫组织化学检测 PRRSV 的肺切片中检测到，表明这些病毒可能已经失去了在 PAM 中复制的能力。这种在 PAM 中无法复制的能力可能与这些组中观察到的较低的传播率和病毒血症发作的延迟有关。
