Recombinant life attenuated vaccine against Argentine hemorrhagic fever

描述(申请人提供)：几种禽流感病毒在人类中引起出血热(HF)疾病，并对其流行地区的公共卫生构成严重威胁。因此，新大陆阿拉伯病毒Junin(JUNV)是阿根廷心力衰竭(AHF)的病原体，这是一种具有出血性和神经系统表现的严重疾病，病死率为15%-30%。此外，JUNV非常稳定，通过气雾剂具有高度传染性，在低剂量时会导致高发病率和死亡率，这些特点使其非常适合作为潜在的生物武器。由于美国缺乏获得许可的疫苗，目前的抗病毒疗法仅限于使用核苷类似物利巴韦林，这种药物只有部分有效，可能会造成显著的毒性，这加剧了人们对阿拉伯病毒感染的担忧。因此，针对JUNV的抗病毒药物的开发一直被视为HHS公共卫生紧急医疗对策企业(PHEMCE)实施计划的首要优先事项之一。因此，针对JUNV感染的医疗对策有资格被BARDA用于国家战略储备。我们已经开发了JUNV的反向遗传系统，并完全从克隆的cDNA中拯救了传染性病毒，包括假丝酵母菌1和致病的Romero株。这一进展为我们提供了一个独特的机会，可以产生JUNV的Candid1(rJUNV/Candid1cSD)和Romero(rJUNV/Romero)菌株的遗传定义明确的种子，用于免疫原性和有效性研究。这项建议旨在提供对rJUNV/Candid1cSD的稳定性、免疫原性和保护性的全面表征，作为开发能够满足未来FDA许可所需的安全性和有效性标准的坦率1疫苗的第一步和必要步骤。为此，我们提出了以下具体目标： 1.确定rJUNV/Candid1cSD的遗传稳定性和表型稳定性。我们建议产生并鉴定rCandid1cSD的主病毒种子(MVS)。我们将使用rCandid1cSD的MVS在不同的细胞底物上进行独立的连续传代，包括FDA批准的用于疫苗生产的细胞系。从每个系列中选择的传代的感染性后代将从遗传学(基因组测序)和表型(生长特性和毒力)进行表征。来自这些研究的遗传和表型信息将被用来产生针对遗传和表型稳定性进行优化的新的rCandid1菌株。 2.检测rJUNV/Candid1cSD疫苗在豚鼠体内的安全性、免疫原性和免疫效果。我们建议对我们的基因定义明确的MVS rCandid1cSD在豚鼠身上的毒力进行全面评估。为此，我们将确定与rCandid1cSD免疫相关的临床参数，包括：体温和体重、整体活动量、血液学和临床病理数据(包括肾和肝脏功能)的评估，以及对JUNV致命攻击的保护。这些研究还将包括在旨在评估MVS的遗传和表型稳定性的研究中发现的相关病毒变体。 3.测定rJUNV/Candid1cSD对普通绒猴(Callithrix Jacchus)的抗JUNV效果。我们建议评价rJUNV/Candid1cSD对JUNV感染的常见绒猴(Callithrix Jacchus)动物模型所致的HF的保护作用。这些研究的结果将与目标2中描述的研究获得的免疫原性数据相关联。

DESCRIPTION (provided by applicant): Several arenaviruses cause hemorrhagic fever (HF) disease in humans and pose a serious threat to public health within their endemic regions. Thus, the New World arenavirus Junin (JUNV) is the etiological agent of Argentine HF (AHF), a severe illness with hemorrhagic and neurological manifestations and a case fatality of 15-30%. In addition, JUNV is very stable, highly infectious by aerosol and causes high morbidity and mortality at low dose, features that make it highly suitable as potential biological weapon. Concerns about arenavirus infections are aggravated by the lack of licensed vaccines in the US and current anti-arenavirus therapies being limited to the use of the nucleoside analogue ribavirin, which is only partially effective and can cause significant toxicity. Accordingly, the development of antiviral drugs against JUNV has been considered as one of the top priorities within the Implementation Plan of the HHS Public Health Emergency Medical Countermeasures Enterprise (PHEMCE). Therefore, medical countermeasures against JUNV infections are eligible for acquisition by BARDA for the Strategic National Stockpile. We have developed a reverse genetic system for JUNV and rescued infectious viruses, both Candid1 and the pathogenic Romero strain, entirely from cloned cDNAs. This advance has provided us with the unique opportunity to generate a genetically well-defined seeds of Candid1 (rJUNV/Candid1cSD) and Romero (rJUNV/Romero) strains of JUNV to be utilized in immunogenicity and efficacy studies. This proposal is designed to provide a comprehensive characterization of the stability, immunogenic and protective properties of rJUNV/Candid1cSD as a first and necessary step for the development of a Candid 1-based vaccine able to meet the safety and efficacy criteria required for future FDA licensing. For this we propose the following specific aims: 1. Determine the genetic and phenotypic stability of rJUNV/Candid1cSD. We propose to generate and characterize a Master Virus Seed (MVS) of rCandid1cSD. We will use the MVS from rCandid1cSD to conduct independent serial passages in different cell substrates, including FDA approved cell lines for vaccine production. Infectious progenies from selected passages from each series will be characterized genetically (genome sequencing) and phenotypically (growth properties and virulence). Genetic and phenotypic information derived from these studies will be used to generate novel rCandid1 strains optimized for genetic and phenotypic stability. 2. To determine the safety, immunogenicity and efficacy of rJUNV/Candid1cSD in guinea pigs. We propose to conduct a comprehensive assessment of the virulence of our genetically well-defined MVS rCandid1cSD in guinea pigs. For this, we will determine clinical parameters associated with immunization of rCandid1cSD including: body temperature and weight, overall activity, assessment of hematological and clinical pathology data covering kidney and liver function, and protection against lethal challenge with JUNV. These studies will also include relevant viral variants identified during studies aimed at assessing the genetic and phenotypic stability of the MVS. 3. Determine the efficacy of rJUNV/Candid1cSD against JUNV in common marmoset (Callithrix jacchus). We propose to evaluate the protective efficacy of rJUNV/Candid1cSD against HF disease caused by the pathogenic rJUNV/Romero strain in the common marmoset (Callithrix jacchus) animal model of JUNV infection. Results from these studies will be correlated with immunogenicity data obtained from studies described in aim 2.