Ultrafiltration before detoxification enhance the purity and efficacy of tetanus toxin during large-scale production of tetanus toxoid vaccine

Abstract

The most effective way to control tetanus (caused by Clostridium tetani) is immunization with tetanus toxoid vaccine. However, the production of tetanus vaccine is a complex process including growth of bacteria, harvesting of toxin, and then conversion of that toxin into potent toxoid vaccine. During production, purification of vaccine either at toxin stage or at toxoid stage is essential. In the present study, effect of purification using ultrafiltration at toxin stage was evaluated on four commercial batches of tetanus vaccine in terms of antigenic content (lf/ml), purity in terms of protein nitrogen, antigenic potential by minimum lethal dose and potential efficacy by maximal toxic value. The standard reference methods as per the WHO manual for the production and quality control of tetanus vaccine were followed. A significant increase in the antigenic content, purity, antigenic potential, and potential efficacy of all four batches was observed after ultrafiltration. The results indicate that ultrafiltration before detoxification is an effective method of tetanus toxin purification. It simultaneously increase the quality of the toxin along with the removal of contaminating agents, which otherwise results in adverse effects during use.