ADJUVANTICITY OF ALUMINUM HYDROXIDE AND CALCIUM-PHOSPHATE IN DIPHTHERIA-TETANUS VACCINES .1.

The potencies of two diphtheria-tetanus vaccines (DT) adsorbed to eith er aluminium hydroxide or calcium phosphate were compared in mice and guinea pigs, The vaccines were made from the same batches of purified toxoids and contained the same amounts of antigens. Immunizations were done once or mice with different doses of vaccine injected undiluted, diluted in saline or diluted in the corresponding adjuvant, The vario us potency assays showed that the adjuvanticity of calcium phosphate w as lower than or equal to aluminium hydroxide, Despite the range of po tency assays done, none of the methods reflected the efficacy of these vaccines in revaccination of humans, A simplified potency assay is su ggested for release of final vaccine formulations to reduce the number of animals in quality control.