Jones Jillian F, Whithear Kevin G, Scott Peter C, Noormohammadi Amir H
School of Veterinary Science, The University of Melbourne, Werribee, Victoria, 3030, Australia.
Avian Dis. 2006 Mar;50(1):82-7. doi: 10.1637/7428-083005R.1.
The onset of protective immunity with MS-H was determined through experimental challenge and compared with the parent strain 86079/7NS. MS-H vaccinates and 86079/7NS inoculates were challenged at 1, 2, 3, 4, 5, and 6 wk after vaccination, then examined 2 wk after challenge for signs of respiratory disease. Serologic results indicated that 100% of MS-H vaccinates had antibodies to MS by 3 wk after vaccination and 100% of 86079/7NS inoculates were positive by 2 wk after inoculation. From 3 wk after vaccination, MS-H vaccinates had a significantly lower incidence of air sac lesions and, from 4 wk after vaccination, a significantly lower air sac lesion severity. In 86079/7NS-inoculated birds, a significantly lower incidence of air sac lesions was observed from 1 wk after inoculation, and air sac lesion severity was significantly lower than the unvaccinated controls at 3 wk after inoculation. It would appear that, under the conditions of this experiment, protective immunity elicited by MS-H appeared at 4 wk after vaccination, slightly later than the appearance of serum antibody. Although the MS-H vaccine was slower to establish protective immunity than 86079/7NS, there was no significant difference between the two strains by 4 wk after vaccination or inoculation.
通过实验攻毒确定了MS-H诱导的保护性免疫的起效情况，并与亲本菌株86079/7NS进行了比较。在接种后1、2、3、4、5和6周对接种MS-H疫苗的鸡和接种86079/7NS的鸡进行攻毒，然后在攻毒后2周检查呼吸道疾病症状。血清学结果表明，接种MS-H疫苗的鸡在接种后3周时100%产生了针对MS的抗体，接种86079/7NS的鸡在接种后2周时100%呈阳性。接种MS-H疫苗的鸡从接种后3周起气囊病变发生率显著降低，从接种后4周起气囊病变严重程度显著降低。在接种86079/7NS的鸡中，从接种后1周起观察到气囊病变发生率显著降低，接种后3周时气囊病变严重程度显著低于未接种疫苗的对照鸡。在本实验条件下，MS-H诱导的保护性免疫似乎在接种后4周出现，略晚于血清抗体的出现。虽然MS-H疫苗建立保护性免疫的速度比86079/7NS慢，但在接种或接种后4周时，这两种菌株之间没有显著差异。
