本文旨在根据前期研究建立的恒河猴感染动物模型, 对同期研制的肠道病毒71 型( EV71) 实验性灭活疫苗免疫动物进行全面的免疫保护性评价。评价指标包括病毒攻击后动物体内病毒载量及病理学变化,根据所得结果进行实验性疫苗免疫后动物在病毒攻击中的感染动力学分析。3 个疫苗剂量( 20 、80、320 EU)免疫的恒河猴均出现不同效价的中和抗体,80 EU 和320 EU 剂量组在二次免疫后第6 周抗体效价达1 ∶128～1∶256, 经104 .5CCID50 病毒鼻腔攻击后均未检出阳性病毒载量。20 EU 剂量组中, 淋巴器官、中枢神经系统及其他主要脏器均出现比对照组低但仍为阳性的病毒增殖现象。病理学方面, 各剂量组免疫恒河猴的中枢神经系统以及肺等器官均未出现相关病理损伤。本实验在确定该疫苗对恒河猴有效保护性的同时, 亦为明确EV71 灭活疫苗免疫剂量提供了直接的实验依据。

Based on an established rhesus monkey model , an entrovirus 71 ( EV71) challenge study was conducted. Responses to viral inf ection were determined following immunization with an inactivated vaccine . All three vaccine doses ( 20 , 80 and 320 EU) induced neutralizing antibody responses in rhesus monkeys . Inthe 80 EUand 320 EUgroups , titers of 1∶128-1∶256 were detected at week 4 after the boost vaccination. After intranasal challenge with 104 .5 CCID50 EV71 , viral load was negative in blood, central nervous system( CNS) , and other organs . Inthe 20 EUgroup , al ow viral load could be detectedin blood , lymph nodes , CNS, and other major organs . The pathol ogical results showed that there was no obvious  damage in the CNS, lung and other organs in all three dosage groups . The findings suggest that this experi mental EV71 vaccine can protect the monkeys fromviral challenge .