Antiretroviral drugs to treat HIV infection (Photo: NIAID | CC-by-2.0)
The results of a major new study into HIV transmission have been announced at the International AIDS Conference in Amsterdam.
The PARTNER 2 study looked at the how effective HIV medication is in preventing the transmission of HIV. It found not a single incidence of HIV transmission between men who are positive and on effective treatment and their HIV negative male partners. This is despite not using condoms.
The first PARTNER study in 2014 looked at sero-discordant couples (where one is HIV positive and one is HIV negative), who have condomless sex.
Where the HIV positive partner is on effective HIV medication and has an undetectable viral load, it found not a single incidence of HIV transmission between the couples. This held true in over 40,000 incidents of condomless sex.
However, the first PARTNER study looked mainly at opposite-sex couples. Although it did include some same-sex couples, researchers wanted to do a follow-up study that looked exclusively at male couples who engage in anal sex. HIV is transmitted more easily via anal sex than vaginal sex.
PARTNER 2 was a 14-country study. It looked at 635 gay couples, in addition to the 337 gay couples already recruited for PARTNER 1.
Participants reported nearly 77,000 acts of condomless sex. The study found not a single incident of HIV transmission when the HIV-positive partner had a viral load under 200.
In fact, together with another study, Opposites Attract, researchers have been unable to find a single case of HIV transmission in 126,000 acts of condomless anal sex between partners with differing HIV status.
‘Zero risk’
Aidsmap, which reported the PARTNER 2 findings, states: ‘It remains the case that the most likely probability, by far, that an HIV-positive person with a viral load under 200 copies/ml can infect their partner is zero.’
‘We looked so hard for transmissions,’ researcher Alison Rodger told aidsmap.com. ‘And we didn’t find any.’
The research is yet further evidence that U = U, or Undetectable = Untransmittable. It’s a message that hundreds of sexual health organizations and advocacy groups worldwide are now backing.
NAM’s Executive Director, Matthew Hodson, said in a statement, ‘This is the moment when science trumps stigma. This is the moment when facts must conquer fear.
‘The knowledge that when we are undetectable we can’t pass the virus on to our sexual partners has the power to encourage people to test and to remain adherent to their treatment. Just as importantly it can have an impact on the way that people with HIV think about themselves, removing some of the stress and fear that many in our communities experience.’
‘People who are on effective and successful treatment cannot pass on HIV to their partners’
Ian Howley, Chief Executive of British health charity LGBT Hero, also welcomed the study’s findings.
‘What the PARTNER 2 study does is prove once again that people who are on effective and successful treatment cannot pass on HIV to their partners. This should be reassuring to every gay and bisexual man who is HIV-undetectable that you are not a danger to anyone and no person should use your status as a way to reject you.
‘However, the results of the PARTNER 2 study will not wipe away the stigma those living with HIV receive overnight. We have to continue to push the message and help educate those who still don’t believe the science behind the U=U movement.’
See also
Australian doctors to tell HIV patients that ‘undetectable = untransmittable’
HIV treatment successful in preventing transmission of virus even without condoms
