Asian seabass, Lates calcarifer farming in Southeast Asia, encounters serious disease challenges caused by Streptococcus agalactiae and Streptococcus iniae. However, a vaccine for disease prevention is not yet available. In this study, we investigated the mucosal and systemic antibody (IgM) response kinetics of the Asian seabass following primary immunization with oil-based formalin-killed vaccines (FKVs) prepared from S. agalactiae and S. iniae (monovalent Sa, monovalent Si, and bivalent Sa-Si) and secondary booster with the respective water-based FKVs. The efficacy of vaccines was subsequently evaluated by an experimental challenge. The results revealed similar antibody response kinetics in both systemic and mucosal systems. However, the immune response in the fish vaccinated with the monovalent vaccines was superior to those fish received the bivalent vaccine in terms of specific antibody titer. The fish that received monovalent vaccines required 1–2 weeks to raise a significant level of specific antibody titer in both systemic and mucosal systems while those vaccinated with bivalent vaccine required three weeks. Following booster at day 21, both systemic and mucosal antibody titers in all vaccinated groups had reached the peak at day 28 and gradually declined in the following weeks but remained significantly higher than control until the end of the experiment (day 63). In the challenge test, both monovalent and bivalent vaccines were found to be highly efficacious, with the relative percentage survival (RPS) ranging from 75 to 85%. In summary, this study explored the 63-days antibody response kinetics (both mucosal and systemic systems) of Asian seabass to monovalent and bivalent inactivated vaccines and confirmed that the combination of S. agalactiae and S. iniae in a single injectable vaccine is possible.

亚洲海鲈，尖吻鲈calcarifer在东南亚养殖，遇到引起严重的疾病挑战无乳链球菌和海豚链球菌。但是，尚无用于预防疾病的疫苗。在这项研究中，我们调查了从无乳链球菌和海豚链球菌制备的油基福尔马林杀死的疫苗（FKV）进行初步免疫后，亚洲鲈鱼的粘膜和全身抗体（IgM）反应动力学。（单价Sa，单价Si和二价Sa-Si）和二级助推器以及各自的水性FKV。随后通过实验挑战评估疫苗的功效。结果揭示了全身和粘膜系统中相似的抗体反应动力学。然而，就特异性抗体效价而言，接种单价疫苗的鱼的免疫反应优于接受二价疫苗的鱼。接受单价疫苗的鱼需要1-2周才能提高全身和粘膜系统的特异性抗体滴度水平，而接种二价疫苗的鱼则需要3周。继第21天加注后，所有接种组的全身和粘膜抗体滴度在第28天均达到峰值，并在接下来的几周逐渐下降，但直到实验结束（第63天）仍显着高于对照。在攻击试验中，发现单价和二价疫苗都非常有效，相对存活率（RPS）为75％至85％。总而言之，这项研究探索了亚洲雪鱼对单价和二价灭活疫苗的63天抗体反应动力学（粘膜和全身系统），并证实了 相对生存率（RPS）介于75至85％之间。总而言之，这项研究探索了亚洲雪鱼对单价和二价灭活疫苗的63天抗体反应动力学（粘膜和全身系统），并证实了 相对生存率（RPS）介于75至85％之间。总而言之，这项研究探索了亚洲雪鱼对单价和二价灭活疫苗的63天抗体反应动力学（粘膜和全身系统），并证实了单一注射疫苗中的无乳链球菌和猪链球菌是可能的。