甲肝减毒活疫苗口服免疫动物后的抗体反应

Antibody Response in Animals Immunized After Oral Delivery of Attenuated Live Hepatitis A Vaccine

用PLAG微粒包裹甲肝减毒活疫苗制成微球口眼免疫恒河猴及昆明种小鼠，用EIA法对HAV-IgM、HAV-IgG、HAV-IgA等抗体进行检测，以筛选一种方便易行的免疫途径。结果表明；恒河猴抗体应答于第3周出现，高峰期在5～6周，达1261mIU／mL，随后逐渐下降，口服加强免疫后，抗体回升，野毒株攻击后，抗体再度回升达1244mIU／mL。初次免疫HAV-IgM滴度为1：4000，加强免疫后滴度为1：1000，野毒株攻击后下降为1：100。对照组仪在野毒株攻击后测到HAV-IgM。小鼠免疫2周后有HAV-IgG抗体产生，4周达高峰，S-IgA抗体1周开始测到，4周达高峰并持续两周后开始下降。微粒包裹疫苗免疫灵长类动物后所诱导产生的抗体应答，对野毒株攻击的保护效果明显。小鼠免疫结果与报道相似，但抗体反应出现的时间较免疫恒河猴的时间有所提前。

The microspheres were prepared by encapsulating live attenuated hepatitis A vaccine with PLA/PLG, and the rhesus monkeys and mice were immunized by such microspheres through oral route. Then serum was collectedto detect the HAV- IgM, HAV-IgG, HAV-IgA with EIA, so as to find a convenient immunization way. Results showed that HAV-IgG in rhesus monkeys was detected in the 3rd week and reached a peak value （1267mIU/mL）, and then decreased by degrees. HAV-IgM titer was 1 ： 4000. After an oral booster was given, the HAV-IgG level increased, and HAV-IgM titer was 1 ：1000. The level reached 1244mIU/mL after challenge with wild virus strain, and HAV-IgM was 1 ： 100. HAV-IgM was detected in the control group only after challenge with wild virus strain. HAV-IgG in mice was detected in the 2nd week and reached a peak value in the 4th week . HAV S-IgA was detected in the 1st week and reached a peak value in the 4th week. Antibody response was induced in the rhesus monkeys after oral delivery of the biodegradable microspheres containing live attenuated HA vaccine. The results in mice were similar with the report but the anti-HAV was present earlier as compared with rhesus monkeys.