Currently, there are no vaccines against HIV (human immunodeficiency virus) and HSV (herpes simplex virus) infections. Condom, when used properly, is the most effective means of prophylaxis against viral transmission. However, there is a significant gender imbalance in condom use because women are not always in control over their use. In addition, women are at least twice as likely as men to contract sexually transmitted infections (STIs) from infected partners.

​

Alternatives to condoms that use established antivirals for HIV prophylaxis come with issues such as antimicrobial resistance and low adherence in practice in high-risk groups. There are also no means other than condoms for prophylaxis against HSV. Co-infection with HIV/HSV results in a vicious cycle of mutual facilitation, as individuals who are carriers of HSV have a three- to fourfold increased risk of contracting HIV.