Identification And Pathogenicity Research Of SP-A Strain Of Mumps Virus

Mumps virus (MuV) belonging to Paramyxoviridae family is an enveloped RNA virus with a non-segmented single-stranded negative-sense genome.As a world-wide communicable viral disease,mumps ,usually transmission in air ,is caused by the mumps virus that has a high morbidity especially in children.Twelve distinct MuV genotypes namely A-L have been defined in according to global epidemiological studies of MuV so far.The mumps vaccines are available and wide-spread used in global countries since the 1970s, the number of reported mumps cases has reduced drastically. All these data seems to elucidate an essential function of mumps vaccine use in the control of numerous epidemics. However, the number of reported mumps cases have increased again in some countries and regions where high coverage levels of vaccines are implemented in recent over 10 years. It has been found that one of the reasons for such phenomena include:first,low coverage rate;second, lower efficacy of single-dose immunization; Other reports implicate that such phenomena is due to the fact that the neutralization antibody induced by viruses with different genotypes are not able to neutralize absolutely viruses with other genotypes. The epidemiological studies of mumps in many regions of China show that the viral strain with genotype F is the main prevalent one in China. whereas the strain with genotype A is used to prepare current vaccine. It may contribute to a fact of current relative high incidence of mumps in Mainland of China. In the meantime, the long-term studies of mumps vaccine use implicate that live attenuated mumps vaccines prepared from viral strains with different genotypes including C, D, G, H and J etc. might have the potential to cause certain number of viral aseptic meningitis cases in vaccinated host populations. Up to now, the clinical manifestation of associated central nervous system in the mumps case infected with genotype F has never been reported. Based upon these information and regional epidemiological data of MuV, it may be justified and will have an applied significance in practice to develop a live attenuated mumps vaccine by purposely targeting at specific genotypes.As a consequence, based upon the previous epidemiological studies of mumps strains with genotypes predominated in a number of provinces in mainland of China, we isolated and cultured a MuV candidate strain of the genotype F that could be used to prepare live attenuated mumps vaccine and pathogenicity in Rhesus monkeys were preliminarily investigated in primary experiments.