鸭瘟鸭病毒性肝炎二联弱毒疫苗的研究　1．最佳配比的筛选、安全性及免疫效力

SIUDY ON BIVALENT ATTENUATED VACCINES AGAINST DP AND DVH 1.THE MOST APPROPRIATE PROPORTION,SAFETY AND IMMUNE EFFICACY TEST

本实验利用鸭瘟鸡胚化弱毒疫苗株（Ｃ－ＫＣＥ株）和鸭病毒性肝炎鸡胚化弱毒株（ＱＬ７９株）制备鸭瘟（ＤＰ）鸭病毒性肝炎（ＤＶＨ）二联苗的最佳配比。制备的二联苗安全，１００倍免疫剂量注射鸭无任何不良反应，通过１日龄不含ＤＰ和ＤＶＨ母源抗体的易感雏鸭连传１０代无毒力返强现象。该二联苗免疫注射后第３天，可获得部分免疫力，血清中抗鸭肝炎病毒（ＤＨＶ）的中和抗体效价达２~６．３，此抗体水平可使鸭下一代获得的母源抗体足够抵抗ＤＨＶ强秦攻击，第３天可有４０％的免疫鸭能抵抗１万倍最小致死量（ＭＬＤ）的鸭瘟病毒（ＤＰＶ）强毒攻击。免疫后第７天，鸭可获得坚强的免疫力，此时鸭血清中抗ＤＨＶ的中和抗体效价达２~７．８，１００％（２０／２０）的免疫鸭能抵抗１万倍ＭＬＤ的ＤＰＶ强毒的攻击，具有良好免疫原性。用二联苗、ＤＰ和ＤＶＨ单苗分别免疫鸭后１０ｄ、６０ｄ和９０ｄ，鸭血清中抗ＤＨＶ和ＤＰＶ的ＥＬＩＳＡ抗体水平相近，差异不显著（Ｐ＞０．０５），表明制备的二联苗对ＤＰ和ＤＶＨ苗的免疫原性影响甚小，对使用二联苗的５群鸭进行长时间的初步跟踪检测表明，二联苗对ＤＶＨ的免疫期可达５．５～６个月，对鸭瘟免疫期可达９个月，与分别使用单苗时基本相同，临床上?

This paper reports that bivalent attenuated vaccines against duck plague(DP) and duck viral hepatitis(DVH) were made by using duck plague virus attenuated strain(CKCE)and duck hepatitis virus serotype I attenuated strain(QL79)The bivalent vaccimes were safe. There was no harm to 1, 15,30, 100 and 200 days old ducks when they were injected with a hundred times vaccination dosage,The bivalent vaccines did not become virulent when they were moculated one day old ducks which had no antibodies gainst DHV and DPV for 10 generations.The titres of neutralizing antibody against DHV were 2￣6.3 and 2￣7.8, and 40 percent and 100 percent ducks could be challenged with ten thousands times MLD of virulent DPV at 3 and 7 days postinoculation. The titres of ELISA antibodies against DHV and DPV were similar when ducks were vaccinated with the bivalent vaccines, DP attenuated vaccines and DVH attenuated vaccines separately.The protection period against DVH could range from 5.5 months to 6 month5, and the protection against DP could be for 9 months.