The Opposites Attract Study has released its interim results showing no transmissions from partner to partner in serodiscordant relationships

banner-oa3The Study, titled Opposites Attract, run by the Kirby Institute in Australia has been studying same-sex relationships where one man was HIV-negative and the other man was HIV-positive with an undetectable viral load – also known as ‘serodiscordant’.

The subject pool was composed of 234 gay male couples – 135 from Australia, 52 from Thailand, and 47 from Brazil.

The project is now half-way through and the interim results show zero partner to partner transmissions.

Professor Andrew Grulich, Chief Researcher on the project, said:

“These are very exciting results that seem to mirror findings from other important international studies of heterosexual couples, which have provided strong evidence that treatment as prevention works,” 

“Essentially, what we are seeing among the gay couples enrolled in Opposites Attract is that HIV transmission is quite unlikely when someone’s viral load is undetectable. In fact, no HIV-negative man in the study has contracted HIV from his positive partner.”

“The true risk of transmission could be anywhere between zero and 4.2% per year, with a very small chance that the per-year risk could be higher than 4.2%”

Previously we’ve seen results from the study which also recorded zero transmissions between HIV-positive undetectable people and their HIV-negative partners. This study looks to bolster those findings and confirm the efficacy of Treatment As Prevention (TASP).

The study is still looking to recruit couples however.

“We still need more gay couples to enrol in Opposites Attract, and we need to continue following up with the couples in the study before we can produce a more conclusive result to fully answer the question of how much HIV treatment reduces HIV transmission between partners in gay, sero-discordant couples.”
said Grulich.

You can find more information on the study here


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