鸡马立克氏病三价活疫苗剂量配比和免疫剂量的研究

Studies on the Ratio of Viruses Component and the Doses of Marek's Trivalent Vaccine

用马立克氏病病毒BJMDV-1株分别攻击由CVI988/B5、HCV2/B5和FC126/B5毒株组成的,剂量配比不相同的马立克氏病(MD)三价活疫苗免疫的鸡群,结果表明MD三价活疫苗中CVI988/B5、HCV2/B5及FC126/B5毒株的合适配比为2:1:2。按照此剂量配比制备的MD三价活疫苗,用RB1B超强毒株进行攻毒,当RB1B攻毒对照组MD阳性率为85.71%时,MD三价活疫苗的半数保护剂量(PD50)均数为111PFU/只,95%置信区间为585～53PFU/只的范围内,并确定MD三价活疫苗的免疫剂量为2500PFU/只。用该剂量对鸡进行MD三价活疫苗免疫,可使鸡体产生抗RB1B超强毒株攻击的坚强免疫力。

The Marek＇s trivalent vaccines with different ratio of viruses component, composed of CVI 988/B5, HCV2/B5 and FC126/B5 strains were evaluated for protection efficacy against BJMDV-1 strain. The result showed that the appropriate ratio of these three viruses was 2： 1： 2. When the positive rate of challenge control was 85.71%, the PD50 mean value of trivalent vaccines prepared according to the virus dose ratio （2： 1： 2） was 111 PFU per chicken challenged with RB1B strain in the trail. In fact, the PDs0 mean value having 95% reliability would be ranging from 585 to 53 PFU per chicken. So it was considered that the appropriate immunity dose of trivalent vaccine would be 2 500 PFU per chicken, and the results showed that the chickens vaccinated with 2 500 PFU per chicken of trivalent vaccine could get strong protection against the highly virulent RB1B strain.