Vaginal sex without condoms is a high-risk route for passing on HIV for both the man and the woman. The risk is greater for the woman, probably because of the type of tissue inside the vagina and cervix. However, the risk of an HIV-positive woman passing on HIV to her male partner during unprotected vaginal sex is also high.

Sexually transmitted infections in either partner can increase the risk (as these can cause inflammation or tissue damage in the genital area), as can other causes of damage to tissue in either partner’s genital area. The risk is also increased if the HIV-positive partner has a high viral load or if the HIV-positive partner is the man and he ejaculates into his partner.

Unprotected vaginal sex can also result in pregnancy. If you have had unprotected sex and are concerned about the possibility of you or your partner becoming pregnant, emergency contraception is available from clinics and from pharmacies without prescription. It may also be appropriate for the HIV-negative partner to take post-exposure prophylaxis (PEP).