Biological Characterization Analysis Of CA16Inactivated Viral Experimental Vaccine Strain

Hand, Foot and Mouth Disease (HFMD) is a common infectious disease found normally in children under5years old. The main clinical symptoms of HFMD are high fever, and herpes around hand, foot and mouth, some patients also show severe neurological diseases-including meningitis, brainstem encephalitis and neurogenic pulmonary edema. Severe HFMD can lead to the death of patient. There were several outbreaks of HFMD happened worldwide, therefore, it is an emergency issue for the controlling, especially in children, of HFMD. There are two main pathogens of HFMD known as Coxsackievirus A16Strain (CA16) and Human Enterovirus71(EV71) respectively. There is relatively not much understanding on the pathogenic mechanism of CA16comparing with EV71. However, as an important pathogen for HFMD, similar to EV71, CA16is able to cause severe clinical cases including severe infection in neurological system, encephalitis and even lethal. Its detection rate in HFMD patients varies from15-55%in different areas. There is so far no safe and effective vaccine and drugs to prevent and treat CA16infection. Therefore, it is important to develop efficient CA16vaccine in order to prevent and control its infection. Based on our previous experiences on enterovirus inactivated vaccine development, especially poliovirus inactivated vaccine, hepatitis A virus inactivated vaccine, and recent EV71inactivated vaccine, together with information on relevant enterovirus polypeptide vaccine, we decided to choose inactivated vaccine form for CA16vaccine development. And the main part of the development is to select and analysis vaccine candidate viral strain. We chose GX-20A candidate strain from several CA16strains separated in varies areas in China using biological and immunological analysis. We then used plaque selection and analysis to further get the candidate cloning strain GX-20A-M. In this research, we used GX-20A and its cloning strain GX-20A-M to adaptive grow in KMB-17cellular substrate. We analyzed the biological features, proliferation features, genetic stability and immunogenicity of the viral strains systemically. Our study provide fundamental knowledge and possibility for viral seed bank establishment and development of CA16inactivated vaccine.