Development of live attenuated influenza virus vaccine

描述（由申请人提供）：流感是一种全球性的传染性病毒性疾病，具有重大的公共卫生问题，每年影响数百万人。流感病毒导致发病率和死亡率增加，仅在美国每年就有2万至4万人死亡，经济损失每年达100亿至200亿美元。疫苗基本上每年都供不应求。此外，有一种禽流感或禽流感病毒构成全球大流行的威胁，没有有效的疫苗，如果发生这种大流行，将需要大量疫苗来防治。随着人口老龄化的加剧，这种风险每年都在增加，新的大流行的可能性正在逼近。因此，迫切需要一种高度减毒活疫苗。我们的初步研究发现，在A/WSN/33（H1N1）病毒中，流感病毒基质蛋白（M1）的一个保守的CCHH基序（假定的锌指基序）可以发生突变，而不影响培养MDCK细胞中的病毒复制。一些CCHH突变病毒在小鼠体内高度减毒，保护小鼠免受致命的WT病毒的攻击。在这个项目中，我们想在A/PR8/34（H1N1）病毒（通常用于制造流感疫苗）中创建这些突变，并测试这些突变对小鼠毒力的影响，细胞培养物和胚胎鸡蛋的生长以及对WT致命病毒攻击的保护效率。此外，将在CCHH突变中加入其他基因的其他突变，并确定其对细胞培养物和胚卵的毒力、稳定性、生长和保护效率的影响。一种高度减毒且无毒的PR8病毒可作为主株用于生产高度减毒流感活疫苗。以这种方式生产的减毒活疫苗的热不稳定性将低于目前使用的冷适应疫苗。活疫苗可以很容易地在细胞培养物或胚胎鸡蛋中生长。活疫苗可以很容易地交付，并且需要更小的剂量来为提供充足疫苗供应的人进行免疫。活疫苗还将对流行病和/或大流行性病毒产生更广泛和持久的保护性免疫。公共卫生相关性：流感是一种全球传染性病毒性疾病，具有重大公共卫生关切，每年影响数百万人。该项目的目标是创造高度减毒的PR8病毒，可作为生产减毒流感活疫苗的主株。减毒活疫苗可以大量生产，易于运送，并将对强毒性流感病毒产生更广泛和持久的保护性免疫。

DESCRIPTION (provided by applicant): Influenza is a global infectious viral disease of great public health concern affecting millions of people every year. Influenza viruses cause increased morbidity and mortality in the range of 20,000-40,000 death/yr in USA alone and economic loss of 10-20 billions of dollars/yr. Vaccines are in short supply essentially every year. Furthermore, there is a bird flu or avian flu virus posing a global pandemic threat against which there is no effective vaccine and massive amount of vaccine will be required to combat the pandemic if and when it occurs. With the increasing aging population, this risk is increasing every year and a possibility of a new pandemic looming. Therefore a highly attenuated live vaccine is urgently needed. Our preliminary studies have identified that in A/WSN/33(H1N1) virus, a conserved CCHH motif (the putative zinc finger motif) of influenza virus matrix protein (M1) can be mutated without affecting virus replication in MDCK cells in culture. Some CCHH mutant viruses were highly attenuated in mice and protected mice against lethal WT virus challenge. In this project, we want to create these mutations in A/PR8/34(H1N1) virus which is commonly used for making influenza vaccine and test the effect of these mutations in mice virulence, growth in cell cultures and embryonated chicken eggs and protection efficiency against WT lethal virus challenge. In addition, other mutations in other genes will be added to CCHH mutations and their effect on virulence, stability, growth in cell cultures and embryonated eggs and protection efficiency will be determined. A highly attenuated and avirulent PR8 virus can be used as master strain for generating highly attenuated live influenza vaccine. Live attenuated vaccine produced in this way will be less thermo-labile than the presently used cold adapted vaccine. Live vaccine can be grown easily in cell culture or in embryonated chicken eggs. A live vaccine can be delivered easily and a smaller dose will be required to immunize people providing plenty supply of vaccine. Live vaccine will also produce broader and long lasting protective immunity against epidemic and/or pandemic viruses. PUBLIC HEALTH RELEVANCE: Influenza is a global infectious viral disease of great public health concern affecting millions of people every year. The goal of this project is to create highly attenuated PR8 viruses which can be used as master strains for generating live attenuated influenza vaccine. Live attenuated vaccines can be produced in mass quantity, delivered easily and will produce broader and long lasting protective immunity against virulent influenza viruses.