Vaccine adjuvants: Functionality and associated risks

Vaccination is one of the major advances in public health, thanks to its essential role in preventing infectious diseases and reducing mortality worldwide. However, despite the proven benefits of vaccines, concerns persist about their safety, particularly that of vaccine adjuvants. The aim of this study is to examine the different types of vaccines, the adjuvants used in their formulation, and their potential involvement in the occurrence of adverse effects. Firstly, this study presents the general principles of vaccination, and its historical development from the work of Jenner and Pasteur to modern genetic engineering technologies. The main types of vaccine are described: live attenuated vaccines, inactivated vaccines, subunit vaccines and recombinant vaccines. The second part is devoted to vaccine adjuvants, substances capable of enhancing and prolonging the immune response induced by antigens. The mechanisms of action of adjuvants are detailed, including the activation of immune cells.