I'll bet you've heard of Chlamydia--the most common (bacterial) sexually transmitted disease (STD). The problem with it is you can develop a silent infection that goes untreated, and can result in damage to your fertility. Scientists are doing research in hopes of developing a vaccine.
More....
http://news.monstersandcritics.com/health/article_
1183926.php/Scientists_work_toward_a_Chlamydia_vaccine
