鸡马立克氏病三价活疫苗剂量配比和免疫剂量的研究

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。

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

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 PD50 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.