113 Epidemics of Acute Gastroenteritis Caused by Viruses and Vaccine Development in China

The leading etiological agents of viral gastroenteritis are group A rotaviruses, noroviruses, adenoviruses (type 40, 41) and astroviruses in China in the last 20 years. The prevailing serotypes of rotaviruses are G type 1, 2, 3, 4 and 9, while G8 has been emerged recently in China. Accordingly, trivalent and hexavalent vaccines are under development by the two Institutes under CNBG. The trivalent oral vaccines are reassortants of VP4 and VP7 genes of human strains and other backbone genes of Lanzhou lamb rotavirus (LLR). The safety of lamb rotavirus vaccine strain has been proved since licensing in 2000 in China. The phase 3 clinical trials of the trivalent vaccines are in the progress in Henan province, China. The hexavalent oral vaccines are reassortants of VP7 genes of human strains and the other genes of UK strain, developed by and collaborated with NIH, USA, and PATH. The preclinical studies at Wuhan Institute of Biological Product have been completed and the hexavalent vaccine is ready for phase 1 clinical study. The novoviruses are increasingly detected in epidemics of acute viral gastroenteritis and spontaneous cases of people of all ages in China, including the rapid spreading of the newly emerged pandemic GII.4 variant (Sydney strain 2012) to China. The new Sydney strains were isolated in different areas and analysis of complete sequence demonstrated the rapid evolution. The surveillances and epidemic studies of these emerging viruses support the development of vaccines against the infections caused by noroviruses. The new variant co-circulated with other genotypes of GI and GII genogroups in human and multiple valent vaccines may needed to be developed.