Visceral leishmaniasis (VL) is a neglected tropical disease caused by Leishmania donovani or Leishmania infantum. Currently, the patients are treated with chemotherapeutic drugs; however, their toxicity limits their use. It would be desirable to develop a vaccine against this infection. In this study, we assessed the efficacy of different vaccine formulations at variable time points. Heat-killed (HK) antigen of Leishmania donovani was adjuvanted with two adjuvants (AddaVax and Montanide ISA 201) and three immunizations at a gap of 2 weeks (wk) were given to BALB/c mice. After 2 weeks of the last booster, mice were given challenge infection and sacrificed before challenge and after 4wk, 8wk, and 12 wk post-challenge. Significant protective immunity was observed in all the immunized animals and it was indicated by the notable rise in delayed-type hypersensitivity (DTH) response, remarkably declined parasite burden, a significant increase in the levels of interferon-gamma (IFN-γ), interleukin-12, interleukin-17 (Th1 cytokines), and IgG2a in contrast to infected control mice. Montanide ISA 201 with HK antigen provided maximum protection followed by AddaVax with HK and then HK alone. These findings elaborate on the importance of the tested adjuvants in the vaccine formulations against murine visceral leishmaniasis.

内脏利什曼病 (VL) 是一种被忽视的热带疾病，由杜氏利什曼原虫或婴儿利什曼原虫引起。目前，患者正在接受化疗药物治疗；然而，它们的毒性限制了它们的使用。人们希望开发一种针对这种感染的疫苗。在这项研究中，我们评估了不同疫苗配方在不同时间点的功效。杜氏利什曼原虫热灭活 (HK) 抗原与两种佐剂 (AddaVax 和 Montanide ISA 201) 一起佐剂，并对 BALB/c 小鼠进行 3 次免疫，间隔 2 周 (wk)。最后一次加强免疫2周后，对小鼠进行攻击感染，并在攻击前以及攻击后4周、8周和12周后处死小鼠。所有免疫动物均观察到显着的保护性免疫力，表现为迟发型超敏反应（DTH）显着升高，寄生虫负荷显着下降，干扰素-γ（IFN-γ）、白细胞介素水平显着增加。 -12、白细胞介素 17（Th1 细胞因子）和 IgG2a 与受感染的对照小鼠相比。含有 HK 抗原的 Montanide ISA 201 提供了最大程度的保护，其次是含有 HK 的 AddaVax，然后是单独的 HK。这些发现详细阐述了所测试的佐剂在针对鼠内脏利什曼病的疫苗配方中的重要性。