Toxoid vaccines

Toxoid vaccines are based on the toxin produced by certain bacteria (e.g.tetanus or diptheria). The toxin invades the blood stream and is largely responsible for the symptoms of the disease. The protein-based toxin is rendered harmless (toxoid) and used as the antigen in the vacccine to elicit immunity. To increase the immune response, the toxoid is adsorbed to alumunium or calcium salts, which serve as adjuvants.