As the HIV epidemic has evolved over three decades, the "just use a condom" message has remained the cornerstone of prevention. But stubbornly high levels of new HIV infections in the UK show we've struggled to always translate this simple message into real life.
Most monogamous couples will decide to stop using condoms at some point, but what if one half of the couple is HIV positive? Until recently, it has been assumed there is no safe option other than condoms for life. But new research into the preventive benefits of HIV treatment (antiretroviral therapy) is set to change this, and could potentially revolutionise the way we think about HIV prevention and safer sex advice.
HIV treatment works by reducing the level of HIV in the body (the viral load) to such an extent that a person's infectiousness is almost zero (clinically referred to as "undetectable"). A big effect of this – in addition to keeping the person healthy – is that the risk of transmitting HIV to another person is dramatically reduced.
Last month we heard the conclusive results of the first global study into HIV "treatment as prevention" – a 96% reduction in transmission risk when the HIV-positive partner received treatment and responded effectively. When put into practice, this means people living with HIV who are on treatment can, like everyone else, consider giving up condoms when their relationship is committed and monogamous.
But before we get carried away, it is not time to throw away our condoms altogether. They are still the best protection against other sexually transmitted infections, so any couple wanting to rely on treatment rather than condoms to prevent HIV transmission must be confident they are both STI free and monogamous. Other STIs in the body can make HIV levels spike upwards, which seriously compromises the effects of treatment as prevention and significantly increases risk of transmission.
The notion of ditching the condoms when one half of a couple is HIV positive also throws up other practical challenges in a relationship. A condom is visible, its use is mutual, and if it fails this is usually evident. By contrast, the level of HIV in a person's body is invisible has been measured at some point in the past (up to four months, usually) and that information has been given to only one of the sexual partners. Very different issues of trust are involved and to rely on this method means relying in both partners' faithfulness, or on their courage to come clean if they have sex with anyone else.
Last year, at the National Aids Trust's seminar on HIV treatment as prevention, we heard stories from couples who were in this situation and trying to navigate their safer sex options in a way that suited them both.
Some couples were happy to rely on treatment as prevention, but for others it was a lot more complex. In some instances the negative partner was happy to rely on treatment but the positive partner was too worried about the risk (however small) of passing HIV on to the one they love. For others it was the opposite, with the HIV-negative partner anxious about risk of infection despite the HIV positive partner's desire to no longer use condoms.
What is clear from people's experiences is that HIV treatment as prevention is not some "quick fix". There remain complex issues of love and trust to negotiate, as well as unlearning the internalised stigma and fear around HIV, which people have lived with for years.
This is not to say that treatment as prevention will only have benefits for those who are in long-term, monogamous relationships. Being on treatment will still reduce infectiousness even if you have more than one partner, but you could not rely on it to prevent transmission in the same way that an exclusive couple might.
Additionally, one of the biggest barriers to HIV treatment as prevention is the fact that at least a quarter of people living with HIV in the UK have not been diagnosed – and therefore are not on treatment.
So with the exception of those in completely monogamous (and honest) relationships, the message is still "use condoms". But the fact remains that people will always make their own decisions based on the level of risk they're prepared to live with.
What we need is clear guidance on how individuals should be advised on using "treatment as prevention" as a safer sex option and this should be combined with renewed efforts to encourage condom use. Crucially, this will require appropriate, accessible support for those people who find using condoms or negotiating their use difficult – a much larger number of people than is usually acknowledged.
Thirty years into the epidemic, an HIV prevention revolution could be upon us. But the basic need for well-resourced, appropriate HIV and sexual health support services remains the same. And while we aren't ready to lay condoms to rest just yet, the "just use a condom" message can now be combined with a new source of encouragement for those diagnosed with HIV that if they commence and stick to their treatment, when the timing is right in their lives there will be another option available to them for safer sex.
