Abstract
Model vaccines have been made by covalently linking Clostridium botulinum type D toxin and Klebsiella pneumoniae capsular polysaccharide antigen to polymerized rabbit serum albumin beads. When injected into rabbits these bead vaccines induced an enhanced production of specific humoral antibody without causing adverse reactions. The adjuvant effect is due to a slow release from the bead structure and offers an alternative to oil emulsions and mineral salt adsorbents.