The present invention is related to antigens from Chlamydia trachomatis which are recognized by specific antibodies from individuals infected with Chlamydia or which can induce T cells from the same individuals to secrete gamma-interferon. The T cell reactive antigens are present in a whole-cell lysate and have apparent molecular weights of 5-12, 16-20, 25-35 and 58-74 kDa as determined by SDS-PAGE. The antigens of the invention are believed to be useful in vaccines but also as diagnostic compositions.
