Preliminary Study On The Influences Of Biological Characteristics Of Improved Culture Medium And Preparation Method For Tetanus Toxoid Vaccines

Tetanus toxoid vaccine is derived from the Clostridium tetani secreted toxoid which was detoxified by methyl aldehyde(0.4%),and the vaccine still sustained its immunogenicity.The purified toxoid vaccine could vaccinate human and animals to protect them from Clostridium tetani infection.However,the vaccine produced in manufacturing techniques employed by the domestic companies had many drawbacks including low purity,low immunogenicity and high side effects,which limited the vaccine application,and optimizing the techniques was pivotal for solving these problems.Therefore,Our research aimed at improving the culture medium and preparation method for the vaccine,and hope to solve the current existing drawbacks.We adjusted the culture medium formula on the basis of cooked meat medium,and the improvements were also made in preparation method including the processes of detoxification,salt precipitation and desalination.Bacteria proliferative ability,toxoid potent,toxoid purity,production and immunogenicity.The results showed that:1.the turbidimetry assay was used to investigate bacterial growth and depict the bacteria-growth curves,we found that improved medium could significantly increase bacteria growth speed(P=0.033).The vaccine titer evaluation assay also proved that the new culture medium improved vaccine density(P=0.032).There was no significant differences between the two manufacturing techniques in terms of virulence.2.BCA assay found that the protein density of Tetanus Toxoid produced by the improved technique was higher than that of traditional methods,but there showed no statistical significance(P=0.605).SDS-PAGE and Western Blot proved that the improved method could significantly increase vaccine purity(P=0.001).3.Animal acute and long-term toxicity experiments demonstrated that the vaccines showed inexistence of exogenous toxic matters,and new method produced vaccine could significantly improve animal survival rate(P=0.027)and sustain the stability of animal body weight comparing to traditional methods.Immunogenic evaluation results showed that the vaccine produced by the new method had higher immunogenicity than the traditional method(P=0.001).In summary,the improved culture medium and preparation method could significantly improve the purity and immunogenicity of the vaccine,decrease its endogenous toxic matters and side effects,and could apply to large-scale production,which could be used as guidance and reference for domestic enterprises.