H2株甲肝减毒活疫苗安全性及免疫效果观察

目的观察单层及悬浮吸附工艺不同收毒时间生产的H2株甲型肝炎减毒活疫苗(以下简称甲肝活疫苗)接种恒河猴的安全性及免疫效果。方法筛选甲肝抗体阴性,丙氨酸转胺酶(ALT)正常的恒河猴15只,随机分为3组,每组5只,下肢静脉注射疫苗1 ml/只。接种3 d内,每天观察有无局部和全身反应,0,2,3,4,6,8周采血测ALT及甲肝抗体,0,4,8周肝穿做组织病理检查,观察到期尸检。结果接种疫苗3 d内,所有恒河猴均无局部和全身反应。观察全程ALT正常,肝脏无特殊组织病理改变。免后4周甲肝抗体全部阳转,单层工艺26 d疫苗、悬浮工艺23和26 d疫苗几何平均滴度(GMT)4周分别为9.2,14.9和27.9;8周分别为32,64和64;悬浮工艺23 d和26 d疫苗猴体免疫效果相似,且两者均明显优于单层工艺疫苗。结论悬浮吸附工艺23 d收毒疫苗接种恒河猴具有较好的安全性和可靠的免疫效果,采用悬浮吸附工艺生产H2株甲肝活疫苗23 d收获病毒较经济和稳妥。

Observation on safety and immune effect of live attenuated Hepatitis A vaccine (H2 strain) with suspension absorption technique in rhesus monkey

Objective Objective To observe the safety and immune effect of live attenuated hepatitis A vaccine(H_2 strain) produced by mono-layer absorption and suspension absorption with different virus harvest period in rhesus monkeys.Methods Fifteen rhesus monkeys with negative anti-HAV and normal level of alanine transaminase(ALT) were selected and divided randomly into 3 groups.A group of 5 animals for 1 specimen and 1?ml of vaccine was injected by IV into each rhesus monkey.The local and systemic reactions were observed within 3 days after injection.Both anti-HAV and ALT were detected at wk 0,2,3,4,6,8 and liver puncture was performed at wk 0,4,8 for histopathological examination.Autopsy was down at the end of observation.Results No local and systemic reactions were observed in any rhesus monkeys within 3 days after vaccination,The ALT levels were normal and no specific liver histopathological change were examined during whole period.The seroconversion rate of anti-HAV was 100% at 4 wk after inoculation.The GMTs were 9.2,14.9,27.9 for mono-layer absorption vaccine(26?d harvest),suspension absorption vaccine(23?d harvest) and suspension absorption vaccine(26?d harvest) at 4 wk and 32,64,64 at 8 wk.The immune effects induced by 2 suspension absorption vaccine were similar,but better than that mono-layer absorption.Conclusion Suspension absorption with 23?d harvest technique vaccine possesses good safety and immune effect in rhesus monkey inoculation.The application of suspension absorption(23?d harvest) technique for production of hepatitis A vaccine(H_2 strain) is economic and practicable.