5th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention: summary of key research and implications for policy and practice – Biomedical prevention

Mark Mascolinli, Rodney Kort

No major findings were reported at the 5th IAS Conference on HIV Pathogenesis, Treatment and Prevention (IAS 2009) on currently enrolled microbicides, pre-exposure prophylaxis (PrEP) or vaccine trials, although important findings in all three areas of biomedical prevention research are expected within the next few years.A study found that daily acyclovir did not reduce HIV transmission, but was a factor in modest reductions in viral load, which could confer some clinical benefit. Research demonstrating rapid viral replication in mucosal tissue and subsequent dissemination throughout the body suggested that research priorities should shift towards a mucosal vaccine. Findings reported in Track C indicated that, in addition to reducing vertical transmission, antiretroviral therapy (ART) also lowers the risk of prematurity, stillbirth and abortion.Challenging concerns about the potential "disinhibiting" effect of ART as prevention, a Kenyan study found that widespread ART encourages greater use of condoms and does not increase the rate of risky sex. Another Kenyan study found that pregnancy increases the risk of HIV transmission in a cohort of serodiscordant couples. Although three randomized trials have conclusively demonstrated that circumcision reduces HIV transmission among heterosexual men, research presented at IAS 2009 found no evidence of a preventive impact for women.