The present invention provides a method of nucleic acid, including DNA,
immunization of a host, including humans, against disease caused by
infection by a strain of Chlamydia, specifically C. pneumoniae, employing
a vector containing a nucleotide sequence encoding OMP (outer membrane
protein) of a strain of Chlamydia pneumoniae and a promoter to effect
expression of the OMP (outer membrane protein) gene in the host.
Modifications are possible within the scope of this invention.