Coping with genetic diversity: the contribution of pathogen and human genomics to modern vaccinology

Lemaire, D.; Barbosa, T.; Rihet, P.

The first vaccines resulted from empirical studies and were mainly composed of whole organisms (live attenuated or killed) or inactivated toxins. The majority of vaccine studies developed later also used conventional approaches to select for appropriate antigens. Antigen selection was a key step in vaccine development in the pre-genomic era but was time-consuming and had many limitations. The properties aimed for in these molecules were: 1) being accessible to the immune system and inducing protective immunity and 2) being conserved within the species and not containing regions of high variability (3). The selection of good candidate vaccine antigens was primarily based on the capacity of induction of protective antibodies, which probably explains why effective vaccines currently available mainly induce a protective humoral immune response (1). More recently, molecular biology methods have been applied to the development of new vaccines, primarily to enable large-scale production of subunit or peptide-based vaccine antigens. Nevertheless, only a small number of available vaccines are based on recombinant antigens.