This often leads to a stronger response. Booster immunization are very effective because they provide the opportunity for new rounds of clonal expansion of memory B and T cells. The mucosal immune system may have additional requirements for initiation of immune responses. Food antigens and normal environmental compounds do not induce an immune response when introduced to mucosal surfaces. Pathogenic microoganisms do induce immune responses.
Adjuvants are substances that enhance the immunogenicity of an antigen.
For example, by increasing interleukin-1 secretion by macrophages. For example, some adjuvants induce interferon production by cells. This cytokine activates T cells. This component of the outer membrane of gram - bacteria is a potent inducer of innate immune responses. In addition, it binds to B cells, triggering them to divide and produce antibody regardless of the specificity of the antibody.