狂犬病口服疫苗在实际储运和环境释放中的消减规律研究

Study on the Reduction of Oral Rabies Vaccines in Actual Storage,Transportation and Environmental Release

为探索冻干剂、咀嚼剂和喷剂三种剂型的rAd5-ΔE1/E3-CGS狂犬病口服疫苗在运输、保存、反复冻融及不同温度下投放时疫苗效价的消减规律,将三种剂型的疫苗经过2~8℃运输48 h,重新入库的疫苗分别-20℃保存1年和反复冻融5次,再将冻融后疫苗分别于2~8℃保存4个月、15℃放置1个月、25℃放置1周和37℃放置3 d,于不同时间点取样检测疫苗效价(lgTCID 50/头份)。结果显示,三种口服疫苗经过2~8℃运输48 h后,效价分别下降至6.25、5.75和6.25,再经过-20℃保存1年和反复冻融5次后效价分别下降至5.67、5.33、5.33和5.33、5.00、5.67。在2~8℃保存4个月后,三种剂型口服疫苗效价均能达到5.00以上;在15℃放置1个月、25℃放置1周以及在37℃放置3 d后,疫苗效价最低分别为3.75、2.50和1.00。研究表明,三种剂型口服疫苗在冷链运输、冷冻保存、反复冻融和低温环境释放条件下具有良好的稳定性,常温环境对咀嚼剂的稳定性影响较小,高温环境会严重降低口服疫苗效价,建议在气温不高于15℃条件下进行rAd5-ΔE1/E3-CGS的环境释放。本研究为狂犬病口服疫苗的野外释放提供了数据支撑,也为流浪动物和野生动物的狂犬病疫苗口服免疫提供了技术支持。

To explore the reduction of oral rabies vaccine rAd5-ΔE1/E3-CGS in three forms during storage,transportation,repeated freezing and thawing and release at different temperatures,vaccines were transported at 2~8℃for 48 hours,and then stored at-20℃for 1 year,and repeated freezing and thawing for 5 times respectively.After freezing and thawing,the vaccines were stored at 2~8℃for 4 months,at 15℃for 1 month,at 25℃for 1 week and at 37℃for 3 days respectively.The titer of oral vaccines were determined at various time points(lgTCID 50/dose).The titer of the oral vaccines after transportation reached 6.25,5.75 and 6.25,respectively.After stored at-20℃for 1 year,and repeated freezing and thawing for 5 times respectively,the titer of the oral vaccines reached 5.67,5.33,5.33 and 5.33,5.00,5.67.Although the vaccine titer of oral vaccines could reach more than 5.00 after storage for 4 months at 2~8℃,the lowest lgTCID 50 was only 3.75 at 15℃for 1 month,2.50 at 25℃for 1 week and 1.00 at 37℃for 3 days.The three oral vaccines showed good stability under the conditions of cold chain transportation,cryopreservation,repeated freezing and thawing,and low temperature environment release.The normal temperature showed the lowest impact on the stability of chewing agents,but the high temperature seriously reduced the virus titers.It is recommended that the environment temperature should be not higher than 15℃when the oral vaccine rAd5-ΔE1/E3-CGS was released.This study provides data support for the environmental release of oral rabies vaccine,and also provides technical support for the oral immunization of rabies vaccine for stray animals and wild animals.