Designing vaccines for the twenty-first century society

Abstract

The history of vaccination clearly demonstrates that vaccines have been highly successful in preventing infectious diseases, reducing significantly the incidence of childhood diseases and mortality. However, many infections are still not preventable with the currently available vaccines and they represent a major cause of mortality worldwide. In the twenty-first century, the innovation brought by novel technologies in antigen discovery and formulation together with a deeper knowledge of the human immune responses are paving the way for the development of new vaccines. Final goal will be to rationally design effective vaccines where conventional approaches have failed.

Keywords: glyco-conjugate; structural vaccinology; technologies; vaccination; vaccine design.

Figure 1

Technologies for vaccine development. Empirical approaches consisting mostly of killed or live-attenuated microorganisms, partially purified components of pathogens (subunit vaccines), detoxified toxins or polysaccharides have represented the starting point in vaccinology, leading to the successful elimination of many devastating diseases. During the last 30 years, several novel technologies such as recombinant DNA technology, glyconjugation, reverse vaccinology, and structural vaccinology are opening the possibility of designing new vaccines previously considered impossible to make. Adapted from Rappuoli et al. (68).

Figure 2

New technologies aimed at interrogating the human B cell repertoire after vaccination or infection are providing for the first time the possibility of isolating broadly neutralizing antibodies that target relevant conserved epitopes. A structural characterization of an antigen in complex with protective antibodies represents the launching point for the design of new immunogens bearing selected relevant protective epitopes to be used for vaccination.