The present invention provides compositions comprising a Chlamydial major outer membrane protein (referenced herein as “MOMP”), from at least one Chlamydial serovar and an adjuvant, characterized in that the adjuvant comprises the product E6020 having CAS Number 287180-63-6. The composition may further comprise at least one carrier system (e.g., emulsion, mineral particle). The MOMP protein may be derived from any species of Chlamydia (e.g., C. trachomatis, C. pneumoniae, C. psittaci, or C. trachomatis MoPn). In preferred embodiments, the composition comprises one or more major outer membrane proteins each derived from different serovars of C. trachomatis. The invention also provides methods of inducing an immune response to a Chlamydia species (e.g., C. trachomatis) in a subject, by administering to the subject a composition of the invention.