Drug Chemistry

Vaccine and Drug Delivery Systems

Vaccine is a material which induces an immunologically mediated resistance to a disease but not necessarily an infection. Vaccines or antigens are generally composed of killed or attenuated organisms or subunits of organisms or DNA encoding antigenic proteins of pathogens. Sub-unit vaccines though they are exceptionally selective and specific in reacting with antibodies often fail to show such reactions in some circumstances such as shifts in epitopic identification center of antibody and are poorly immunogenic. Delivery of antigens or vaccine from oil-based adjuvants like Freunds adjuvant lead to a reduction in the number of doses of vaccine to be administered but due to the toxicity concerns such as inductions of granulomas at the injection site and are not widely used. FDA approved adjuvants for human uses are aluminium hydroxide and aluminium phosphate in the form of alum.