Adjuvant

An adjuvant is a pharmacological or immunological agent that modifies the effect of other agents. Adjuvants may be added to a vaccine to boost the immune response to produce more antibodies and longer-lasting immunity, thus minimizing the dose of antigen needed. Adjuvants may also be used to enhance the efficacy of a vaccine by helping to modify the immune response to particular types of immune system cells: for example, by activating T cells instead of antibody-secreting B cells depending on the purpose of the vaccine. Adjuvants are also used in the production of antibodies from immunized animals. There are different classes of adjuvants that can push immune response in different directions, but the most commonly used adjuvants include aluminum hydroxide and paraffin oil. An adjuvant is a pharmacological or immunological agent that modifies the effect of other agents. Adjuvants may be added to a vaccine to boost the immune response to produce more antibodies and longer-lasting immunity, thus minimizing the dose of antigen needed. Adjuvants may also be used to enhance the efficacy of a vaccine by helping to modify the immune response to particular types of immune system cells: for example, by activating T cells instead of antibody-secreting B cells depending on the purpose of the vaccine. Adjuvants are also used in the production of antibodies from immunized animals. There are different classes of adjuvants that can push immune response in different directions, but the most commonly used adjuvants include aluminum hydroxide and paraffin oil. Immunologic adjuvants are added to vaccines to stimulate the immune system's response to the target antigen, but do not provide immunity themselves. Adjuvants can act in various ways in presenting an antigen to the immune system. Adjuvants can act as a depot for the antigen, presenting the antigen over a longer period of time, thus maximizing the immune response before the body clears the antigen. Examples of depot type adjuvants are oil emulsions. An adjuvant can also act as an irritant, which engages and amplifies the body's immune response. A tetanus, diphtheria, and pertussis (DPT) vaccine, for example, contains small quantities of inactivated toxins produced by each of the target bacteria, but also contains some aluminium hydroxide. Such aluminium salts are common adjuvants in vaccines sold in the United States and have been used in vaccines for more than 70 years. Adjuvants are needed to improve routing and adaptive immune responses to antigens. This reaction is mediated by two main types of lymphocytes, B and T lymphocytes. Adjuvants apply their effects through different mechanisms. Some adjuvants, such as alum, function as delivery systems by generating depots that trap antigens at the injection site, providing a slow release that continues to stimulate the immune system. This is now under debate, as studies have shown that surgical removal of these depots had no impact on the magnitude of IgG1 response. Although immunological adjuvants have traditionally been viewed as substances that aid the immune response to the antigen, adjuvants have also evolved as substances that can aid in stabilizing formulations of antigens, especially for vaccines administered for animal health.