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（由申请人提供）：世界需要一种高效的疟疾疫苗。Sanaria PfSPZ疫苗由无菌、纯化、冷冻保存的辐射减毒PfSPZ组成，在NIH临床试验中保护了100%的志愿者。在马里、坦桑尼亚、赤道几内亚（EG）和美国，371名受试者通过直接静脉接种（DVI）接种了疫苗。已经确定了安全性、耐受性、高等级保护、受控人类疟疾感染后的异源保护、田间持久保护、3次剂量的有效性和5倍100%保护剂量的安全性。Sanaria已与世界卫生组织举行会议，计划进行资格预审，并成立一个由DVI管理的PfSPZ疫苗技术咨询小组。2015-16年，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。计划于2017年底在美国提交第一份许可证。PfSPZ/方案数量、剂量数量和/或完成免疫方案的时间的减少以及效力的延长将降低成本并改善实施。能够通过皮肤或肌内途径进行免疫接种将提高对幼儿进行免疫接种的能力，并便于经验不足的人员进行免疫接种。为此，我们研究了增强/延长免疫应答的佐剂。传统和实验佐剂，包括多种toll样受体配体，不起作用，可能是因为疫苗由减毒活生物体组成，并且已知没有许可的佐剂可以增强CD 8 + T细胞介导的免疫力，而CD 8 + T细胞介导的免疫力似乎是PfSPZ疫苗保护效力的基础。新型糖脂7 DW 8 -5结合CD 1d并刺激iNKT细胞，在用辐照过的约氏疟原虫子孢子（PSPZ）免疫的小鼠中具有强佐剂作用，并且当通过DVI施用PSPZ时能够减少至1个剂量（75%保护），并且当皮内施用时能够减少至4至2个剂量（70%-100%保护）。保护期至少持续14周。在一周内的4个DVI剂量的2x 103个纯化的、冷冻保存的具有和不具有7 DW 8 -5的HSPPySPZ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，该方案对于旅行者和大规模施用活动是理想的。在非人灵长类动物（NHP）中，具有PfSPZ疫苗的7 DW 8 -5耐受性良好;大大增强了疫苗接种后2.5个月脾CD 8+和CD 4 + T细胞应答的幅度。这些发现支持开发7 DW 8 -5，用于通过血管内和传统途径给予PfSPZ疫苗，以降低商品成本，快速免疫并提高保护的持久性。在本项目中，我们将在小鼠和NHP中评估7 DW 8 -5与啮齿动物、人和猿SPZ的关系，并按照cGMP生产7 DW 8 -5。实现本提案的具体目标将为PfSPZ疫苗与7 DW 8 -5一起施用的第一阶段临床试验提供基础，并最终将该组合用于旅行者/军人的快速和成本有效的免疫接种以及大规模疟疾消除运动。

 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.