The present invention features peptides of a PorB polypeptide, which PorB
peptides are useful in production of antibodies that bind the full-length
PorB polypeptide and as a therapeutic agent. In specific embodiments the
invention features a composition comprising one or more PorB peptides
(other than a full-length PorB polypeptide), which peptides contain at
least one epitope that can elicit Chlamydia-neutralizing antibodies. The
invention also features methods for induction of a protective immune
response against infection by Chlamydia and Chlamydiophila.