Peptides are disclosed that include SEQ ID NO:1, SEQ ID NO: 2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, and SEQ ID NO:6, or a conservative variant or mimic thereof, wherein the conservative variant or mimic specifically binds an antibody that specifically binds SEQ ID NO:1, SEQ ID NO: 2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID or NO:6. These peptides are of use in generating an immune response against C. pneumoniae, or in preventing infection with against C. pneumoniae.