The invention relates to vaccines, and particularly to vaccines active against pathogenic bacteria including Clostridia species, such as C. difficile, and Bacillus species, such as B. anthracis and B. cereus. The invention is concerned with the use of nucleic acids and proteins as antigens for use in vaccine design and construction, and to the vaccines per se. The nucleic acids and proteins are also useful in diagnostic test kits and methods for the detection of Clostridium spp. and Bacillus spp. infections.
