Good news: Effective HIV treatment protects against transmission during sex without a condom. This is the most important result of the interim evaluation of the PARTNER study. This Europe-wide study investigates the protective effect of HIV therapy during anal and vaginal intercourse without a condom. And it goes even further: gay couples are being sought as study participants.
The interim results of the PARTNER study were presented yesterday at the international CROI conference in Boston. The study is based on data from more than 700 serodifferent - i.e. one partner is HIV-positive, one is negative - gay and heterosexual couples who (also) had anal (and/or vaginal) intercourse without a condom. Thanks to HIV therapy, the HIV-positive partner had to have a viral load of less than 200 copies per millilitre of blood plasma and take the HIV medication consistently.
"This is extremely good news," says Armin Schafberger, Medical Officer at Deutsche AIDS-Hilfe. "According to study leader Jens Lundgren, around 50 to 100 transmissions to the HIV-negative partners would have been expected if the HIV-positive partners in the study had not received antiretroviral treatment. The HIV therapy therefore prevented many infections." However, it cannot be concluded from this interim result that the risk is zero, Schafberger continues. "Statistically, transmissions would have been possible with more couples if the observation period had been longer. For this reason, the study will be continued until 2017 and will be expanded to include 450 additional homosexual couples. We are inviting gay serodifferent couples, i.e. one partner is HIV-positive and one HIV-negative, to take part in the PARTNER study. The sooner we have more gay couples, the sooner we will have good results."
Further results in a nutshell:
- The researchers estimate that the HIV-negative partners studied have had condomless sex a total of around 45,000 times in the course of the study to date.
- Interesting: 16 per cent of the HIV-negative homosexual men examined were diagnosed with sexually transmitted infections (STIs), primarily gonorrhoea and syphilis. Such STIs increase the risk of HIV transmission when the HIV viral load is high, but fortunately they do not appear to have a major effect when the viral load is low.
