Elaboration of a method of stabilizing the protective fraction of pertussis microbes

A method for stabilizing adsorbed preparations of the protective fraction of B. pertussis has been developed; according to this method, a colloid suspension of protective protein in phosphate buffer is obtained, the protein is then adsorbed on aluminium hydroxide gel and lyophilized with 10% of sucrose. If stored at 4 degrees C, these dried preparations have been found to retain their immunogenicity for 1 year.