Science took a back seat to politics during one of the most controversial sessions of the XVII International AIDS Conference in Mexico City – one that took place hours before the conference had officially opened. At a specially convened satellite event, seven influential panellists discussed the implications of the Swiss Federal AIDS Commission’s controversial January statement – that an undetectable viral load in the blood renders an individual uninfectious, under optimal conditions.
It became clear during the two-hour meeting that although many on the panel and in the audience argued that there should be honest and effective communication of the facts, ‘facts’ and strongly-held beliefs were often conflated, resulting in even more confusion.
Part of the problem, explained Professor Pietro Vernazza, Head of Infectious Diseases at Cantonal Hospital, St. Gallen, Switzerland and President of the Swiss Federal AIDS Commission, was that the Swiss consensus statement on the effect of treatment on transmission was misinterpreted by some to mean that treatment should replace condoms as a prevention strategy. Others believe that the statement vindicates the practice of condomless sex between non-monogamous partners of different or unknown status practised by small numbers of highly informed HIV-positive gay men with undetectable viral load in some developed countries.
“We never thought of it as a statement that was to be delivered worldwide,” Professor Vernazza told the meeting, but rather “it was meant only to be delivered to Swiss physicians to help them discuss sexual risk-taking with their patients and their steady partners.”
Another problem, noted Professor Vernazza, was that the title of the statement – Les personnes séropositives ne souffrant d’aucune autre MST et suivant un traitment antirétroviral efficace ne transmettent pas le VIH par voie sexuelle (HIV-positive people with no other STIs and on effective antiretroviral therapy do not transmit HIV sexually) – “was misleading and I apologise for that. We wouldn’t do that again.”
He added, however that the statement had noted that even condom use was not 100% ‘safe’, but that the risk was “in a comfortable range that people can live a normal life. We would place sex under antiretroviral therapy in a similarly safe range, but we only consider this ‘safe’ under special conditions,” he said. The conditions include fully suppressive treatment for at least six months, with excellent adherence, regular viral load monitoring, and the certainty that the HIV-positive person and their regular HIV-negative partner have no other sexually transmitted infections (STIs).
“We also made it clear that the only person who can assess perfect adherence and regular check-ups would be a steady partner, and that it should only be the informed [HIV-negative] partner who could assess the risks for themselves.”
The statement, he said, was “good news for a small number of people, but [for everyone else] prevention messages remain unchanged.”
Nevertheless, he conceded that although it was based on an expert assessment of current biological, epidemiological and ecological evidence, the motivation for the statement was primarily political. He said that since it was possible for the Swiss state to prosecute HIV-positive people who had unprotected sex with consenting, fully informed HIV-negative partners under HIV exposure laws, this statement could be used in court to show that if an individual was on successful treatment they could not possibly expose – or transmit – HIV.
He added that the statement was also made to help serodiscordant couples who were unwilling – or unable – to access sperm-washing or other assisted reproduction techniques in order to conceive safely.
Finally, and most importantly, he said, the statement was made because there was a discrepancy between what some doctors told their patients in private and what they were prepared to say in public, and, consequently, to ward off the “risk of uncontrolled diffusion” of information.