A glycolipid adjuvant to promote dose sparing, accelerate immunization schedules and extend durability of high-level protection with a live attenuated sporozoite malaria vaccine

 描述(申请人提供)：世界需要一种高效的疟疾疫苗。Sanaria(R)PfSPZ疫苗由无菌、纯化、冷冻保存的辐射减毒PfSPZ疫苗组成，在NIH的临床试验中保护了100%的志愿者。该疫苗已通过直接静脉接种(DVI)在马里、坦桑尼亚、赤道几内亚(EG)和美国的371名受试者中接种。建立了安全性、耐受性、高等级保护、控制人类疟疾感染后的异种保护、现场持久保护、三剂有效和100%保护量5倍的安全性。Sanaria已与世界卫生组织举行会议，计划进行资格预审，并建立一个由DVI管理的PfSPZ疫苗技术咨询小组。2015-16年，该疫苗将在坦桑尼亚、肯尼亚(500名婴儿)、马里、布基纳法索、EG、德国和美国接受DVI评估。美国的第一份许可证申请计划于2017年底提交。减少PfSPZ/方案的数量、剂量和/或完成免疫方案的时间，并延长疗效，将降低成本并改善执行情况。能够通过皮肤或肌肉途径接种疫苗将增加为幼儿接种疫苗的能力，并促进经验较少的人员进行免疫接种。为此，我们研究了增强/延长免疫反应的佐剂。传统佐剂和实验佐剂，包括多个Toll样受体配体，不起作用，可能是因为疫苗由减毒活菌组成，而目前还没有获得许可的佐剂可以增强CD8+T细胞介导的免疫，这似乎是对抗PfSPZ疫苗的保护效力的基础。一种新的糖脂，7DW8-5，它结合CD1d并刺激iNKT细胞，在辐射约氏疟原虫子孢子(IrrPySPZ)免疫的小鼠中具有很强的佐剂作用，当DVI给药时，7DW8-5能减少到一剂(保护75%)，皮下给药时从4剂减少到2剂(保护70%-100%)。保护措施持续了至少14周。在一周的2×103纯化、冷冻保存的irrPySPZ中，有和没有7DW8-5的四剂DVI分别保护了96%(15/16)和44%(7/16)的小鼠(p=0.0059)，提高了加速免疫方案的可能性，这将是旅行者和大规模接种活动的理想方案。在非人灵长类动物中，接种PfSPZ疫苗的7DW8-5耐受性良好；接种后2.5个月，脾CD8+和CD4+T细胞反应显著增强。这些发现支持7DW8-5的开发，用于通过血管内和传统途径注射的PfSPZ疫苗，以降低商品成本、快速免疫和增加保护的持久性。在本项目中，我们将用啮齿动物、人和猿猴SPZ在小鼠和NHP中评估7DW8-5，并按照cGMPs制造7DW8-5。实现这项建议的具体目标将为使用7DW8-5的PfSPZ疫苗的第一阶段临床试验奠定基础，并最终将这种组合用于旅行者/军队的快速且经济有效的免疫接种和大规模消除疟疾运动。

 DESCRIPTION (provided by applicant): The world needs a highly effective malaria vaccine. Sanaria(r) PfSPZ Vaccine, composed of aseptic, purified, cryopreserved radiation attenuated PfSPZ, protected 100% of volunteers in an NIH clinical trial. The vaccine has been administered by direct venous inoculation (DVI) to 371 subjects in Mali, Tanzania, Equatorial Guinea (EG), and USA. Safety, tolerability, high-grade protection, heterologous protection after Controlled Human Malaria Infection, durable protection in the field, efficacy with 3 doses and safety at 5x the 100% protective dose, have been established. Sanaria has met with the World Health Organization to plan for pre-qualification and establishment of a Technical Advisory Group for PfSPZ Vaccine administered by DVI. In 2015-16, the vaccine will be assessed by DVI in Tanzania, Kenya (500 infants), Mali, Burkina Faso, EG, Germany, and USA. The first licensure submission in USA is planned for late 2017. Reduction in the number of PfSPZ/ regimen, number of doses, and/or time to complete an immunization regimen, and prolongation of efficacy will reduce costs and improve implementation. Being able to immunize by cutaneous or intramuscular routes will increase capacity to immunize young infants and facilitate immunization by less experienced personnel. To these ends, we have studied adjuvants that augment/prolong immune responses. Traditional and experimental adjuvants, including multiple toll-like receptor ligands, do not work, likely because the vaccine is composed of live-attenuated organisms and no licensed adjuvants are known to enhance the CD8+ T cell-mediated immunity which appears to underlie protective efficacy against PfSPZ Vaccine. A novel glycolipid, 7DW8-5, which binds CD1d and stimulates iNKT cells, has strong adjuvant effects in mice immunized with irradiated P. yoelii sporozoites (irrPySPZ), and enabled reduction to one dose when irrPySPZ were administered by DVI (75% protection) and from 4 to 2 doses when administered intradermally (70%-100% protection). Protection lasted for at least 14 weeks. Four DVI doses during a week of 2x103 purified, cryopreserved irrPySPZ with and without 7DW8-5 protected 96% (15/16) and 44% (7/16) of mice respectively (p=0.0059), raising the possibility of an accelerated immunization regimen that would be ideal for travelers and mass administration campaigns. In non-human primates (NHPs), 7DW8-5 with PfSPZ Vaccine was well tolerated; greatly enhancing the magnitude of splenic CD8+ and CD4+ T cell responses 2.5 months post vaccination. These findings support development of 7DW8-5 for use with PfSPZ Vaccine administered both by intravascular and traditional routes to allow for reduced cost of goods, rapid immunization and increased durability of protection. In this project we will assess 7DW8-5 with rodent, human, and simian SPZ in mice and NHPs, and manufacture 7DW8-5 in compliance with cGMPs. Accomplishing the Specific Aims of this proposal will provide the foundation for the first phase 1 clinical trial of PfSPZ Vaccine administered with 7DW8-5, and eventual use of this combination for rapid and cost effective immunization of travelers/military and for mass malaria elimination campaigns.