Antibody responses in adult and neonatal BALB/c mice to immunization with novel Bordetella pertussis vaccine formulations

Abstract

A balanced or Th-1 type immune response is required for effective clearance of many pathogens such as Bordetella pertussis, the causative agent of whooping cough. Since current acellular pertussis vaccines induce limited Th-1 type immune responses, novel vaccine formulations are needed to induce protective immunity in the infant in the earliest stages of life. Here, we developed a novel vaccine platform consisting of genetically detoxified pertussis toxoid (PTd) with multiple adjuvant components including CpG oligodeoxynucleotides, polyphosphazenes, and cationic innate defence regulator peptides. Co-formulation with these immunomodulators increased the serum IgG2a and IgG1 antibody titres in adult mice when compared to immunization with each of the selected adjuvants or immunization with PTd antigen alone. When used in combination, these adjuvants were able to induce a superior IgG2a response in both adult and neonatal mice, when compared to antigen alone or commercial vaccines. The increased response observed when using this adjuvant formulation was also initiated earlier and, moreover, was maintained over a period of greater than 22 months. The adjuvant platform also showed an ability to induce an immune response in a greater number of mice as compared to antigen alone. This suggests that this uniquely adjuvanted vaccine induces a stronger and more balanced immune response with an earlier onset of this response than vaccination with PTd antigen alone.