This Week in HIV Research: Do You Believe in U=U?

Results from a large online survey highlight another potential obstacle to full adoption of U=U as an HIV prevention strategy: Many people still don’t believe in it.

Among 111,747 U.S. men belonging to a sexual minority who responded to an online survey, 53% thought U=U was either completely or somewhat accurate, researchers reported in the Journal of Acquired Immune Deficiency Syndromes. Among participants living with HIV, 84% rated U=U as either completely or somewhat accurate, although that percentage was lower among those who were not virally suppressed or who had suboptimal adherence to treatment. Among HIV-negative respondents, recent HIV testing (within the past six months) was associated with a much higher likelihood of believing U=U was correct.

Acceptance of the message increased among new enrollees over the duration of the study. “These finding[s] suggest that HIV prevention services continue to have the intended effect of increasing HIV prevention knowledge,” study authors commented.

Study results show the importance of framing the U=U message correctly, the authors noted. Case in point: Even people who rated U=U as accurate often thought that the risk of HIV transmission from the virally suppressed partner was greater than zero.

The study authors recommended talking about risk reduction in the context of enhancing protection against HIV; this approach could help people compare U=U to other prevention strategies, such as condoms or pre-exposure prophylaxis (PrEP).

People living with HIV (PLWH) in serodiscordant relationships often inaccurately report an undetectable viral load, according to a small U.S. study among men living with HIV whose primary male partner is HIV negative. This has implications for HIV prevention, since the U=U strategy only works if the partner living with HIV has an undetectable viral load. The study was reported in Journal of Acquired Immune Deficiency Syndromes.

The study involved 120 men in Atlanta, Boston, and Chicago. Researchers compared their self-reported viral load with biomarkers from blood samples taken at the same time. Overall, 73% of participants’ reports matched their biomarkers. However, in 20% of those reporting viral suppression, blood analysis did not confirm this.

Study authors hypothesized that these participants had been virally suppressed at their prior health care visit, but suboptimal adherence to treatment since then caused their viral load to rise above the level of detection. They called for:

• Educating PLWH and their partners about the potential for fluctuations in viral load levels.
• Reminding PLWH about the importance of adherence for maintaining viral suppression.
• Explaining to HIV-negative partners how they can support their partner’s HIV treatment.

If people living with HIV had the ability to self-test their viral load between health care visits, that could help couples decide when additional measures to prevent HIV transmission are necessary. Developing the necessary technology should be a research priority, study authors concluded.

A person’s HIV transmission cluster—i.e., the group of people with whom their HIV strains are genetically linked—can yield clues about their potential to slip through the HIV care continuum, according to a large U.S. study.

The data, which were reported in Clinical Infectious Diseases, were derived from a retrospective study of 5,226 PLWH diagnosed in Los Angeles County between 2010 and 2014. They indicated that PLWH in genetically linked HIV transmission clusters that were growing rapidly spent more time virally suppressed before their viral load rebounded than those in slow-growing clusters. However, high-growth clusters were more likely to be composed of people with CD4 cell counts of ≥500 cells/ml at diagnosis than were slow-growth clusters.

“We acknowledge that cluster growth is influenced by access to and engagement with care, including HIV testing,” study authors noted. Once diagnosed, participants progressed through the care continuum at similar rates as others in their cluster: If others with a genetically linked virus took longer to become virally suppressed, so did they. Overall, median time between diagnosis and linkage to care was less than one month and diagnosis to viral suppression was six months.

Study authors suggested that services focused on HIV care linkage/restoration could place a priority on people within genetic clusters in which others have taken longer than usual to reach the next stage in the continuum, or had fallen out of care altogether.

From 2012 through 2017, dolutegravir (Tivicay) uptake increased faster than other integrase strand transfer inhibitors in Europe and Australia, with relatively low discontinuation rates across the entire drug class, researchers reported in Journal of Acquired Immune Deficiency Syndromes.

The study found that 52% of 9,702 participants started dolutegravir, 20% started elvitegravir (Vitekta), and 28% started raltegravir (Isentress) during the five-year period. Six months later, 9% of participants had stopped taking their integrase inhibitor, with raltegravir discontinued most often, usually to simplify treatment. The other common reason for switching treatment regimens was toxicity, in particular nervous system toxicity on dolutegravir.

Women discontinued their integrase inhibitor more often than men, even after adjusting for body mass index—i.e., side effects leading to discontinuation did not appear to be related to women’s generally lower body weight relative to men, upon whom recommended drug dosages were based. “Our results suggest that further research is needed on the safety of [integrase inhibitors] in women, who are often underrepresented in HIV research,” study authors commented. They also called for more research into adverse events experienced by patients receiving integrase inhibitors.