Novel Approaches for the Design of Vaccines against Infectious and Autoimmune Diseases

The renaissance in vaccine research during the past decade led to several new approaches towards vaccine development. One is the evaluation of the potential of synthetic peptides corresponding to sequences of microbial proteins, comprising defined epitopes, to elicit antibodies with capacity to inactivate the respective pathogens and to protect against infection. Focusing on influenza, a novel approach – synthetic recombinant vaccines – was developed, in which the relevant epitopes are expressed by genetic engineering. Oligonucleotides coding for three influenza epitopes stimulating B cells, T helper cells and cytotoxic T lymphocytes (CTLs), respectively, were individually inserted into the flagellin gene of a Salmonella vaccine strain. The protective immunity, even against a lethal challenge, conferred by a vaccine, comprising a mixture of these three constructs, persisted for at least seven months and was effective against several strains of influenza. These results are indicative of the potential of such synthetic constructs as a long-range and broad-spectrum vaccines against influenza in other viruses, including HIV. A similar approach led also to protective immunization against the parasite Schistosoma mansoni..