National Centre for Foreign Animal Disease, 1015 Arlington Street, Winnipeg, Manitoba R3E 3M4, Canada.
National Centre for Foreign Animal Disease, 1015 Arlington Street, Winnipeg, Manitoba R3E 3M4, Canada.
Vaccine. 2021 Mar 1;39(9):1420-1427. doi: 10.1016/j.vaccine.2021.01.042. Epub 2021 Jan 30.
Foot-and-mouth disease (FMD) is a severe, highly contagious viral disease that affects a wide variety of domestic and wild cloven-hoofed animals. FMD vaccines can play a vital role in disease control and are very widely used globally each year. However, due to the diversity of FMDV, the choice of FMD vaccine is still a huge challenge. In this study, 45 FMDV/A isolates were phylogenetically categorized into three topotypes: ASIA (n = 31), AFRICA (n = 10), and EURO-SA (n = 4). Three sera collected from vaccinated cattle with FMDV A22/IRQ/24/64, A/IRN/05, and A/ARG/01 were used to evaluate their antigenic relationship (r) with the field isolates. The IRQ/24/64 serum demonstrated a 39% (17/44) match (r ≥ 0.3) to the field isolates, whereas IRN/05 serum and ARG/01serum showed an 18% (8/44) and a 2% (1/44) match (r ≥ 0.3) to the field isolates, respectively. The A22/IRQ/24/64 matched with isolates mainly from topotype ASIA, with limited cross-topotype match with isolates from topotypes AFRICA and EURO-SA. However, the A/IRN/05 did not show a cross-topotype match with topotype AFRICA isolates and A/ARG/01 failed to match any isolates from topotypes ASIA and AFRICA. After analyzing the amino acid variation of the known antigenic sites of 45 strains of FMDV/A, it was found that together antigenic sites 1 and 3 contributed about 71% of the amino acid changes to the vaccine evaluated. Based on the capsid sequences, the FMDV/A evolved unequally among topotypes. The topotypes of ASIA and AFRICA evolves faster than that of EURO-SA. The FMDV/A continues to show a high level of genetic diversity driven by a high substitution rate, purifying selection, and positive selection concentrated on antigenic sites or near antigenic sites. The current research shows the challenges of the FMDV/A vaccine selection and emphasizes the importance of continuous monitoring of antigenic evolution for the selection of effective vaccines.
口蹄疫（FMD）是一种严重的、高度传染性的病毒疾病，影响广泛的家养和野生偶蹄动物。FMD 疫苗在疾病控制中可以发挥重要作用，每年在全球范围内都得到广泛使用。然而，由于 FMDV 的多样性，FMD 疫苗的选择仍然是一个巨大的挑战。在这项研究中，45 株 FMDV/A 分离株被分为三个拓扑型：ASIA（n=31）、AFRICA（n=10）和 EURO-SA（n=4）。从接种了 FMDV A22/IRQ/24/64、A/IRN/05 和 A/ARG/01 的牛血清中采集了三株血清，用于评估它们与田间分离株的抗原关系（r）。IRQ/24/64 血清与 44 个田间分离株中的 39%（17/44）相匹配（r≥0.3），而 IRN/05 血清和 ARG/01 血清分别与 44 个田间分离株中的 18%（8/44）和 2%（1/44）相匹配（r≥0.3）。A22/IRQ/24/64 与主要来自拓扑型 ASIA 的分离株相匹配，与来自拓扑型 AFRICA 和 EURO-SA 的分离株的交叉拓扑型匹配有限。然而，A/IRN/05 与拓扑型 AFRICA 分离株没有交叉拓扑型匹配，A/ARG/01 未能与来自拓扑型 ASIA 和 AFRICA 的任何分离株匹配。在分析了 45 株 FMDV/A 的已知抗原位点的氨基酸变异后发现，共同抗原位点 1 和 3 对评估疫苗的氨基酸变化贡献约 71%。基于衣壳序列，FMDV/A 在拓扑型之间的进化是不均匀的。ASIA 和 AFRICA 的拓扑型比 EURO-SA 的进化速度更快。FMDV/A 继续表现出高水平的遗传多样性，这是由高替代率、纯化选择和集中在抗原位点或附近抗原位点的正选择驱动的。目前的研究表明了 FMDV/A 疫苗选择的挑战，并强调了为选择有效的疫苗而对抗原进化进行持续监测的重要性。
