近年来，手足口病已经成为危害儿童健康的重要传染病。2010年我国该病病例达1,795,336例，重症患者数超过2.1万，其中死亡病例905例，比前一年均有显著增加，疾病流行形势非常严峻。加快研发手足口病疫苗，有效预防和控制疾病，是我们的首要任务。由于人体对手足口病主要病原体EV71的免疫保护机理还不清楚，给该病疫苗的研发带来困难。
近日，《病毒学期刊》（Virology Journal）发表了中科院上海巴斯德研究所冷启彬研究组的最新研究成果，揭示了手足口病患儿抗EV71的中和抗体反应规律，有助于深入理解和揭示手足口病患者针对EV71的获得性免疫反应，对疫苗开发和评价具有重要意义。
该研究组与安徽省阜阳市疾病预防控制中心合作，对手足口病患儿、健康儿童和对该病具有免疫力的成人分别进行了对比研究，发现80%的患儿在感染后第一天的抗体水平已经达到成人所具有的抗EV71中和抗体水平，第二天抗体水平已与病后7天的水平相当，表明患儿表现出临床症状时已经在感染后至少五天以上，且获得性免疫反应已经接近于最高水平。总体上，手足口病患儿产生的抗EV71中和抗体水平与疾病严重程度没有相关性。此外，即便是对该病完全具有免疫力的成人也有超过16%免疫没有抗EV71中和抗体，表明与疾病严重程度有关的可能是细胞免疫，而不是中和抗体，提示在手足口病疫苗的设计和临床保护评价方面，应考虑细胞免疫反应的因素。
此项研究得到了中国科学院“百人计划”及疫苗项目启动经费、赛诺菲-安万特-中科院上海生命科学研究院优秀青年人才基金的资助。(生物谷 Bioon.com)
doi:10.1186/1743-422X-8-306
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Neutralizing antibody response in the patients with hand, foot and mouth disease to enterovirus 71 and its clinical implications
Chunfu Yang, Chaoyang Deng, Junfeng Wan, Liye Zhu and Qibin Leng
Enterovirus 71 (EV71) has emerged as a significant pathogen causing large outbreaks in China for the past 3 years. Developing an EV71 vaccine is urgently needed to stop the spread of the disease; however, the adaptive immune response of humans to EV71 infection remains unclear. We examined the neutralizing antibody titers in HFMD patients and compared them to those of asymptomatic healthy children and young adults. We found that 80% of HFMD patients became positive for neutralizing antibodies against EV71 (GMT = 24.3) one day after the onset of illness. The antibody titers in the patients peaked two days (GMT = 79.5) after the illness appeared and were comparable to the level of adults (GMT = 45.2). Noticeably, the antibody response was not correlated with disease severity, suggesting that cellular immune response, besides neutralizing antibodies, could play critical role in controlling the outcome of EV71 infection in humans.
