In 2006, experts in the United States conducted a 1-year study on the reliability of condoms and concluded that condoms can reduce the risk of HIV infection by 85% among eight STDs: AIDS, syphilis, gonorrhea, chlamydia, soft chancre, lymphogranuloma venereum, condyloma acuminatum, and genital herpes; they can reduce the risk of gonorrhea transmission from women to men by 49% to 100%.
However, they do not prevent transmission from men to women; there is no evidence that condoms are effective in preventing human papillomavirus infection (condyloma acuminatum). There is still a lack of sufficient epidemiological evidence for the effectiveness of prevention of the remaining five STDs.