Since late 2018, foot-and-mouth disease (FMD) has reemerged and rapidly swept through pig farms in North and Central Vietnam, despite widespread use of commercial FMD vaccines. To investigate the FMD virus (FMDV) strains responsible for the current epidemics, 40 FMDV samples were collected from 17 provinces during November-December 2018, and the VP1 coding genes were sequenced and analyzed. Phylogenetic analysis and sequence comparisons revealed that all of the reemerging Vietnamese FMDVs belonged to the Mya-98 lineage of the O/Southeast Asia topotype (O/SEA/Mya-98) and shared high nucleotide (99.06-100% identity) and amino acid (97.65-100% identity) sequence similarity with each other. The study results suggested that the reemerging FMDVs originated from local Vietnamese strains. Field viruses had different amino acids in the antigenic sites of VP1 when compared to the strains used in the vaccines. The present study provides an important basis for vaccine selection in the battle against FMD in Vietnam.

中文翻译：

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O / SEA / Mya-98谱系口蹄疫病毒是导致2018年底越南广泛流行的原因。

自2018年底以来，尽管广泛使用商业FMD疫苗，口蹄疫（FMD）仍在越南北部和中部重新出现并迅速席卷整个养猪场。为了调查造成当前流行病的口蹄疫病毒（FMDV）菌株，于2018年11月至12月期间从17个省收集了40个FMDV样本，并对VP1编码基因进行了测序和分析。系统发育分析和序列比较表明，所有重新出现的越南FMDV都属于O /东南亚拓扑型（O / SEA / Mya-98）的Mya-98谱系，并共享高核苷酸（99.06-100％同一性）和氨基酸（97.65-100％的同一性）序列彼此相似。研究结果表明，再次出现的口蹄疫病毒源于越南当地菌株。与疫苗中使用的菌株相比，野病毒在VP1的抗原位点具有不同的氨基酸。本研究为越南对抗口蹄疫的疫苗选择提供了重要依据。