Abstract: A method for developing vaccines and treatments against pathogens associated with biological warfare, cardiac disease, cancer, and emerging infectious diseases is to analyze the sequences of proteases of the pathogens and determine which peptide antigens will be useful in treating or preventing the effects of one or more pathogens as vaccines or to provide passive immunity. The sequences of the selected proteases are used to screen the genomes of other pathogens to produce broad spectrum vaccines and treatments that target one or several pathogens. Amino acid sequences of the peptide antigens and immunogenic compositions comprising them are also contemplated.