Researchers may soon be able to develop a vaccine for chlamydia, the most common sexually transmitted bacteria in the world.

Researchers at Children's Hospital of Pittsburgh said that they found a strain of the disease that does not cause damage to an infected animal in testing.

The researchers, led by Toni Darville, MD, chief of the Division of Pediatric Infectious Diseases at Children’s, identified a plasmid-deficient strain of Chlamydia that, when investigated in an animal model of genital tract infection, failed to cause disease. Plasmids are small molecules of DNA.

Dr. Toni Darville, who led the research said that if a similar strain that normally infects humans could be found, it could be turned into a vaccine.

Though common, chlamydia often has mild symptoms or is unnoticed, though it can cause damage to reproductive organs.

In the study, the "plasmid-deficient" strain was given to mice, who did not develop the damage usually seen.

Results of their study are published in the Sept. 15 issue of the Journal of Immunology.