Study Of The Biological Characteristics Of The Rabies Virus Strain AGV And Large-scale Culture

Rabies is an acute zoonotic disease caused by the rabies virus, which haswide epidemic and high mortality. The fatality is almost100%once symptomscome up, and vaccination is the only way to control and eliminate the rabies.The effectiveness of the rabies vaccine is considerably essential as they aremainly used for post-exposure prophylaxis, and the virus seed is a key factorto produce safe and effective rabies vaccine for human use.aGV vaccine strain derived from fixed rabies strain aG that is adapted inVero cells not more than15generations, which is demanded by thepharmacopoeia. The work was done autonomously by enterprisesrespectively. Nowadays, aGV strain has been approved for production ofrabies vaccine (Vero cells) for human use. However, there is still have notmade a systematical study of the biological characteristics of the vaccine strainculturing in Vero cells, which restrictes the improvement of vaccine quality.Based on current studies of rabies virus and its characteristics, rabies fixedvirus3aG strain was inoculated to Vero cells for adaptive passage in thisarticle, and virus seed bank (aGV9，the main seed bank; aGV12，the workseed bank) was established according to the Chinese Pharmacopoeia(Volume Ⅲ,2010Edition). The biological characteristics study indicates that:The aGV seed had typical bullet-like shape, the evolope and spikes could beobserved under the electron microscope; The virulence of virus strainincreased with increasing passages，and was maintained at1～5×108FFU／ml from passage8to12．The homologies of glycoprotein gene sequence andamino acid sequence of aGV9strain were96.95%and98.86%to those of3aGrespectively，the major antigenic sites remains unchanged which took onstable heredity. The virus strain showed good adaptability to Vero cells，ofwhich the peripheral pathogenicity decreased, and no adventitious agents were detected. The neutralization indexes of aGV9and aGV12were5011and15848respectively,which showed that the virus strain had quite higherimmunoginicity.The virus strain wered cultured for3continuors batches in bioreactor, andthe antigen content of the harvest virus liquid was up to8~10IU/ml, which wasconcentrated and purified to prepared into freeze-dried vaccine for human use.The overall tests of the vaccine indicated that it meet all the indexes of theChinese Pharmacopoeia (Volume Ⅲ,2010Edition).The results above suggested that the aGV strain adapted in this studymight be used for production of rabies vaccine for human use. And combiningthe bioreactor technology, we may be able to produce safe, efficient andeconomic rabies vaccine for human use, to improve the vaccine supply indomestic market and ease the high rabies epidemic situation in China.