Immunizing Antigens and Constituents of Vaccines

The need to develop safe and efficacious vaccines ranks amongst the most important challenges for human medicine. Throughout history, most vaccines have been developed using live attenuated organisms, killed whole organisms or inactivated toxins (referred to as toxoids). Recent efforts have focused on utilizing technologies such as recombinant DNA methods to develop DNA and subunit vaccines, as well as conjugate vaccines. The extensive knowledge of immunological mechanisms and host pathogen interactions can contribute to the design of effective vaccines. Vaccines are essential factors in active immunization, performing this activity mainly via immunizing antigens, and they may contain several added substances. Vaccine preservatives and adjuvants are the leading ones, while all ingredients have substantial roles and must have a licence together with the vaccine product. Adjuvants constitute the most studied components of vaccine additives, enhancing and moderating the immune response. The introduction of new adjuvants and concomitant new vaccine formulations for protection from HIV, hepatitis C, malaria and other “difficult” diseases, as well as the development of therapeutic vaccines for chronic diseases and cancer will be required in the near future.