ABSTRACT
SIGNIFICANT EFFECTS OF ADJUVANTS IN VACCINE IMMUNIZATION A vaccine adjuvant should boost the potency and/or the longevity of specifi c immune response to antigens as seen by a reduction in the antigen dosage used and/or the number of immunizations. An adjuvant also should be associated with minimal or no toxicity ( 1 ). In attenuated live vaccines where adjuvants are not used, foreign antigens using pathogen-associated molecular patterns activate pattern recognition receptors (PRRs) inducing both innate immunity and adaptive immunity. With newer vaccines that use highly characterized recombinant antigens, a diminished ability to induce immune protection is present unless an adjuvant is used ( 2 ). For certain diseases such as cancer, the immune response induced by protein-or peptide-based vaccine (i.e., the type-2 T helper (Th2) cell response) needs to be complemented by a Th1biased, antigen-specifi c cytotoxic T lymphocyte (CTL) response. Hence, an adjuvant should induce both antigen-specifi c Th1 and CTL responses ( 2 , 3 ) ( Fig. 17.1 ).
