Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon City, Gyeongsangbuk-do 39660, Republic of Korea.
Korea Disease Control and Prevention Agency, Osong Health Technology Administration Complex, 187, Osongsaengmyeong 2-ro, Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do 28159, Republic of Korea.
Vaccine. 2021 Mar 19;39(12):1701-1707. doi: 10.1016/j.vaccine.2021.02.025. Epub 2021 Feb 20.
Two type O commercial vaccines, the O/Campos and O/Primorsky/2014 vaccines, were studied to evaluate the in vivo efficacy in pigs against heterologous virus challenge with the O/SKR/Jincheon/2014 virus (O/SEA/Mya-98 lineage) isolated in Korea in 2014. The in vivo challenge results indicated that both vaccines induced a high heterologous virus neutralization test (VNT) titer by a single injection and successfully protected specific pathogen-free (SPF) pigs from challenge infection. To determine the optimal vaccination age, a field trial with each vaccine was conducted with three one-shot-vaccinated groups that were injected at 8, 12, or 14 weeks of age and one two-shot-vaccinated group that was injected at 8 and 12 weeks of age in the pig farms. In these field trials, the improved serological performance at 20 and 24 weeks of age expected with vaccination at 12 or 14 weeks of age was not observed, although improved serological results were expected as the result of decreasing interference of maternally derived antibodies (MDAs), as MDAs waned with age. In addition, delayed vaccination resulted in MDA depletion at 14 weeks of age. Therefore, the optimal age for primary vaccination with two different formulated vaccines was 8 weeks old in pigs, considering that MDAs could provide a protective immunity against foot-and-mouth disease (FMD) infection. Prolonged significantly higher VNT titers of immunized pigs were demonstrated in the two-shot-vaccinated groups. In total, the effectiveness of the two vaccines was demonstrated through efficacy tests and field trials in pigs.
两种 O 型商业疫苗，即 O/Campos 和 O/Primorsky/2014 疫苗，被研究用于评估其在猪体内对异源病毒挑战的功效，使用的病毒是 2014 年在韩国分离的 O/SKR/Jincheon/2014 病毒（O/SEA/Mya-98 谱系）。体内挑战结果表明，这两种疫苗在单次注射后均能诱导出高异源病毒中和试验（VNT）滴度，并成功保护无特定病原体（SPF）猪免受挑战感染。为了确定最佳接种年龄，在猪场中对每种疫苗进行了一项现场试验，其中三个单次接种组分别在 8、12 或 14 周龄时注射，一个两剂接种组在 8 和 12 周龄时注射。在这些现场试验中，在 12 或 14 周龄时接种，预期在 20 和 24 周龄时血清学性能会有所提高，但由于母体来源抗体（MDAs）的干扰减少，预期血清学结果会有所提高，因为 MDAs 会随着年龄的增长而减少。此外，延迟接种会导致 14 周龄时 MDAs 耗尽。因此，考虑到 MDAs 可以提供针对口蹄疫（FMD）感染的保护免疫力，在猪中进行两种不同配方疫苗的初次接种的最佳年龄为 8 周龄。两剂接种组的免疫猪的 VNT 滴度显著延长且更高。总的来说，通过在猪中的功效测试和现场试验证明了这两种疫苗的有效性。
