Tan Rhh, Hodge A, Klein R, Edwards N, Huang J A, Middleton D, Watts S P
College of Public Health, Medicine and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia.
Zoetis, Veterinary Medicine Research and Development, Parkville, Victoria, Australia.
Aust Vet J. 2018 May;96(5):161-166. doi: 10.1111/avj.12694.
To determine the antibody responses to a commercial Hendra virus vaccine (Equivac® HeV) in a field environment.
A group of 61 horses received a primary vaccination course comprising two doses administered 3-6 weeks apart (V1, V2) and a 3rd dose (V3) given 6 months after the second. This was followed by booster vaccinations at 12 monthly intervals (V4, V5). Antibody titres were assessed using a virus-neutralisation test.
Neutralising antibodies against HeV were not detected prior to vaccination. Antibodies were detected in 54/57 horses at 3 weeks after V1 and 51/51 had titres ≥ 32 at 8 weeks after V2. At 6 months after V2, antibody titres decreased in most (31/34) horses and were not detected in three horses. A rapid increase in antibody titres was recorded in 35/36 horses at 1 week following V3. By the first annual booster vaccination (V4), antibodies were still detectable in 29/29 horses, although titres had decreased; in 26/29 horses, titres remained ≥ 32. All horses showed an increase in antibody titres after V4. There was no statistically significant increase in mean antibody titre after V5, compared with after V4.
Horses administered Equivac® HeV, using a primary vaccination course followed by annual booster vaccinations, mounted an effective secondary immune response and acquired antibody responses that were consistent with protective immunity against HeV in the form of virus-neutralising antibodies. No adverse events were observed after vaccine administration.
在野外环境中确定对一种商业化亨德拉病毒疫苗（Equivac® HeV）的抗体反应。
一组61匹马接受了初次疫苗接种疗程，包括间隔3 - 6周接种两剂（V1、V2），并在第二剂接种6个月后接种第三剂（V3）。随后每隔12个月进行一次加强接种（V4、V5）。使用病毒中和试验评估抗体滴度。
接种疫苗前未检测到针对亨德拉病毒的中和抗体。V1接种3周后，54/57匹马检测到抗体，V2接种8周后，51/51匹马的抗体滴度≥32。V2接种6个月后，大多数（31/34）匹马的抗体滴度下降，3匹马未检测到抗体。V3接种1周后，35/36匹马的抗体滴度迅速上升。到首次年度加强接种（V4）时，29/29匹马仍可检测到抗体，尽管滴度有所下降；26/29匹马的滴度仍≥32。所有马匹在V4接种后抗体滴度均升高。与V4接种后相比，V5接种后平均抗体滴度无统计学显著升高。
使用初次接种疗程随后每年进行加强接种的方式接种Equivac® HeV疫苗的马匹产生了有效的二次免疫反应，并获得了与以病毒中和抗体形式存在的针对亨德拉病毒的保护性免疫一致的抗体反应。疫苗接种后未观察到不良事件。
