副鸡嗜血杆菌B型分离株免疫原性的比较和疫苗株的筛选

利用分离自我国不同地区的3株B型副鸡嗜血杆菌菌株及0222标准株分别制作油乳剂灭活疫苗免疫无鸡传染性鼻炎病史的鸡群，通过攻毒保护试验和HI抗体测定，分析比较了其免疫原性，以筛选适用于制备疫苗的菌株。结果表明：不同地区的分离株在致病性和免疫原性上存在-定的差异，TJ-1株疫苗免疫鸡对TJ-1和DL-1株的保护作用可达90％和91．7％，对BJ-1株的保护率为63．6％，具有相对较好的保护作用，目前可以作为疫苗株使用。在各免疫组试验鸡中，0222株和BJ-1株免疫鸡群的血清抗体水平较高，但这可能与血凝抑制试验所采用的抗原是由0222株制备的及BJ-1株在抗原性上可能更接近于0222株有关。DL-1和TJ-1株疫苗免疫鸡的抗体水平都很低，但其免疫保护却要强于0222和BJ-1株疫苗免疫鸡。由此说明B型株因菌株之间免疫原性的差异使得HI抗原的选择难度增加。

Comparison of antigenicity of several B serovar isolates of Haemophilus paragallinarum in China and selection of vaccine strain

The inactivated oil adjuvant vaccines were prepared with different isolates from several sites, and the efficacy of these vaccines were compared by challenging and antibody test to evaluate antigenicity of different isolates. The results showed that there are some difference among the strains from different sites. TJ-1 immunized chicken achieved 90.0%, 91.4% and 63.6% of protective rates for challenge against TJ-1, SD-1 and BJ-1 respectively, so TJ-1 could be the most suitable vaccine strain at this time. The HI test showed that the 0222 and BJ-1 got higher HI titer maybe because of using 0222 strain as antigen. The study indicated that the difficulty to build the relationship between the HI titer and protective rates in B serovars.