Turner J W, Liu I K M, Flanagan D R, Bynum K S, Rutberg A T
Physiology and Molecular Medicine, Medical College of Ohio, Toledo 43614-5804, USA.
Reprod Suppl. 2002;60:177-86.
Porcine zona pellucida (PZP) immunocontraception was investigated for possible use in free-roaming wild horses in the western USA. A protocol of two injections (3-4 weeks apart) of vaccine lasting 1 year was first used and a single-injection controlled-release vaccine of 1 year duration was developed and tested in the field. Studies of a presumptive vaccine of 2 year duration were initiated. The parameters of anti-PZP antibody titre response, pregnancy testing and offspring production were used, and PZP vaccine was found to provide up to 94% infertility in free-roaming wild mares. In addition, a single-injection PZP vaccine of 1 year duration and containing a controlled-release component of PZP in a polymer matrix can provide infertility equivalent to the two-injection PZP vaccine. All the PZP vaccine preparations tested were associated with a return to normal fertility within 1 year. During the course of these studies, attention was given to practical aspects of management application of PZP contraception. Preparation of the controlled-release portion of the vaccine in pellets, which fit into the needle of a dart or syringe, has simplified vaccine handling and permitted long-term storage of the controlled-release component. Vaccine delivery is now performed using a jabstick on captured mares restrained in a field stock chute during routine horse gathers. Provision of a vaccine-training programme has maximized personnel safety during vaccine preparation and use.
对猪透明带（PZP）免疫避孕法进行了研究，探讨其在美国西部自由放养的野马中应用的可能性。首先采用了一种方案，即间隔3至4周进行两次疫苗注射，有效期为1年，随后研发了一种有效期为1年的单次注射控释疫苗并在野外进行了测试。还启动了对一种推测有效期为2年的疫苗的研究。研究采用了抗PZP抗体滴度反应、妊娠检测和后代生产等参数，发现PZP疫苗可使自由放养的野生母马的不育率高达94%。此外，一种有效期为1年、在聚合物基质中含有PZP控释成分的单次注射PZP疫苗，其不育效果与两次注射的PZP疫苗相当。所有测试的PZP疫苗制剂在1年内均可使生育能力恢复正常。在这些研究过程中，还关注了PZP避孕法管理应用的实际问题。将疫苗的控释部分制成适合装入飞镖或注射器针头的药丸，简化了疫苗处理过程，并使控释成分能够长期保存。现在，在常规马匹聚集期间，使用刺棒对关在野外牲畜斜槽中被捕获的母马进行疫苗接种。提供疫苗培训计划最大限度地保障了疫苗制备和使用过程中的人员安全。
