Since the publication of the complete genome of a pathogenic bacterium in 1995, more than 50 bacterial pathogens have been sequenced and at least 120 additional projects are currently underway. Faced with the expanding volume of information now available from genome databases, vaccinologists are turning to epitope mapping tools to screen vaccine candidates. Bioinformatics tools such as EpiMatrix and Conservatrix, which search for unique or multi-HLA-restricted (promiscuous) T cell epitopes and can find epitopes that are conserved across variant strains of the same pathogen, have accelerated the process of epitope mapping. Additional tools for screening epitopes for similarity to 'self' (BlastiMer) and for assembling putative epitopes into strings if they overlap (EpiAssembler) have been developed at EpiVax. Tools that map proteasome cleavage sires are available on the Internet. When used together, these bioinformatics tools offer a significant advantage over traditional methods of vaccine design since high throughput screening and design is performed in silico, followed by confirmatory studies in vitro. These new tools are being used to develop novel vaccines and therapeutics for the prevention and treatment of infectious diseases such as HIV, hepatitis C, tuberculosis, and some cancers. More recent applications of the tools involve deriving novel vaccine candidates directly from whole genomes, an approach that has been named 'genome to vaccine'.