Lim Hui Xuan, Poh Chit Laa
Centre for Virus and Vaccine Research, School of Science and Technology, Sunway University, Bandar Sunway, Kuala Lumpur, Selangor, Malaysia.
Centre for Virus and Vaccine Research, School of Science and Technology, Sunway University, Bandar Sunway, Kuala Lumpur, Selangor 47500, Malaysia.
Ther Adv Vaccines Immunother. 2019 Nov 21;7:2515135519888998. doi: 10.1177/2515135519888998. eCollection 2019.
Enterovirus A71 (EV-A71) is one of the major causative agents of hand, foot and mouth disease (HFMD) in the world, infecting mostly infants and young children (<5 years of age) in Asia. Approximately 2 million cases of HFMD were reported in China each year, of which approximately 45-50% were due to EV-A71. Most of the HFMD infections caused by EV-A71 usually result in mild symptoms with rashes and ulcers in the mouth. However, virulent strains of EV-A71 can infect the central nervous system and cause severe neurologic diseases, leading to reduced cognitive ability, acute flaccid paralysis and death. The lack of understanding of cellular immunity for long-term protection from the HFMD disease represents a major obstacle for vaccine development. In particular, the role of innate and T cell immunity during HFMD infection remains unclear and there is evidence suggesting the importance of CD4 and CD8 T cells for protective immunity. Currently, no US FDA-approved vaccine is available for EV-A71. Although the inactivated vaccines produced in China are highly effective (vaccine efficacy >95%), they lack the cellular immunity required for long-term protection. In this review, we discuss the findings that support the protective roles of innate and T cell immunity against EV-A71 infection, which will provide the knowledge needed for the urgent development of efficacious vaccines that will confer long-term protection.
肠道病毒A71（EV - A71）是全球手足口病（HFMD）的主要病原体之一，主要感染亚洲的婴幼儿（<5岁）。中国每年报告约200万例手足口病病例，其中约45 - 50%由EV - A71引起。大多数由EV - A71引起的手足口病感染通常导致轻微症状，伴有皮疹和口腔溃疡。然而，EV - A71的强毒株可感染中枢神经系统并导致严重的神经疾病，导致认知能力下降、急性弛缓性麻痹和死亡。对长期预防手足口病的细胞免疫缺乏了解是疫苗开发的主要障碍。特别是，手足口病感染期间先天免疫和T细胞免疫的作用仍不清楚，有证据表明CD4和CD8 T细胞对保护性免疫很重要。目前，美国食品药品监督管理局（FDA）尚未批准用于EV - A71的疫苗。虽然中国生产的灭活疫苗非常有效（疫苗效力>95%），但它们缺乏长期保护所需的细胞免疫。在这篇综述中，我们讨论了支持先天免疫和T细胞免疫对EV - A71感染具有保护作用的研究结果，这将为迫切开发能提供长期保护的有效疫苗提供所需的知识。
