Adjuvants Adjuvants Adjuvants are substances that nonspecifically enhance the immune response to any immunogen when they are mixed and injected together.
Most adjuvants act by creating a depot for the antigen.
That is, they release the antigen slowly and continuously from the injection site, so the immune system gets maximum exposure to the antigen. Some adjuvants also induce a mild inflammatory reaction that causes antigen presenting cells and lymphoyctes to migrate to the site. This ensures that the immunogen will encounter many potentially immunoreactive cells. However, Freund's adjuvant are not used on humans because it can cause severe reactions.