Ebola virus (EBOV) is one of the most virulent pathogens known to humans. Neutralizing antibodies play a major role in the protection against EBOV infections. Thus, an EBOV vaccine capable of inducing a long-lasting neutralizing antibody response is highly desirable. We report here that a heterologous prime-boost vaccine regimen can elicit durable EBOV-neutralizing antibody response in mice. A chimpanzee serotype 7 adenovirus expressing EBOV GP (denoted AdC7-GP) was generated and used for priming. A truncated version of EBOV GP1 protein (denoted GP1t) was produced at high levels in Drosophila S2 cells and used for boosting. Mouse immunization studies showed that the AdC7-GP prime/GP1t boost vaccine regimen was more potent in eliciting neutralizing antibodies than either the AdC7-GP or GP1t alone. Neutralizing antibodies induced by the heterologous prime-boost regimen sustained at high titers for at least 18 weeks after immunization. Significantly, in vivo challenge studies revealed that the entry of reporter EBOV-like particles was efficiently blocked in mice receiving the heterologous prime-boost regimen even at 18 weeks after the final dose of immunization. These results suggest that this novel AdC7-GP prime/GP1t boost regimen represents an EBOV vaccine approach capable of establishing long-term protection, and therefore warrants further development.

埃博拉病毒（EBOV）是人类已知的最强毒的病原体之一。中和抗体在针对EBOV感染的保护中起主要作用。因此，非常需要能够诱导持久的中和抗体应答的EBOV疫苗。我们在这里报告，异源的初免-加强疫苗方案可以在小鼠中引起持久的EBOV中和抗体反应。产生了表达EBOV GP的黑猩猩血清型7腺病毒（表示为AdC7-GP），并用于引发。果蝇大量生产了截短形式的EBOV GP1蛋白（称为GP1t）S2细胞，用于加强免疫力。小鼠免疫研究表明，与单独使用AdC7-GP或GP1t相比，AdC7-GP初免/ GP1t加强疫苗方案在诱发中和抗体方面更有效。免疫后，异源初免-加强疗法诱导的中和抗体在高滴度下持续至少18周。重要的是，体内攻击研究表明，即使在最终免疫接种后的第18周，接受异源初免-加强疗法的小鼠中，记者EBOV样颗粒的进入也被有效地阻断了。这些结果表明，这种新颖的AdC7-GP初免/ GP1t加强方案代表了能够建立长期保护的EBOV疫苗方法，因此值得进一步开发。