Development Of Analytical Method For The Characterization Of HPV Vaccine And Its Application In The Study Of Influences Of Vaccine Preservatives On Antigens

Thimerosal is an organic mercury-containing compound,which was added into some biological products and pharmaceuticals as the preservative to prevent the growth of bacteria and fungi.It is the most widely-used vaccine preservative.Nowadays,the preservative is still required in the multi-dose vaccines,inactivated vaccines and toxoid.Thimerosal hydrolyzes spontaneously to thiosalicylic acid and ethyl mercury in aqueous solution*The ethyl mercury could interact with available thiol group in the protein solution.Therefore,the protein in vaccine could be adversely affected due to the thiol modification.Thus,the understanding on the impacts of thimerosal on characteristics and functional attributes of antigens are still much needed.In this work,specific effects of thimerosal and other alternative preservatives on the antigenicity and immunogenicity of HPV VLPs were evaluated.The monoclonal antibody panel targeting HPV18 VLP was obtained by screening of hybridoma cells.After comprehensive characterization and classification,six mAbs obtained here are selected to establish the multi-sites immunochemical analytical methods.The effect of thimerosal on the antigenicity and immunogenicity of HPV VLP was investigated in vitro and ex vivo in a quantitative manner.And the integrity of antigen epitopes was measured by the neutralization mAbs.Besides,the structural alterations were observed on HPV18 VLP in the presence of thimerosal through cryo-EM and 3D reconstruction.Then,the effects of four alternative vaccine preservatives on the binding activity and thermal stability of HPV18 VLP were investigated.Besides,the effect of different preservatives on the infection ability of HPV18 pseudovirus was also studied.These works provide some reference for the research and development of multi-dose vaccine formulations and for the selection of vaccine preservatives.