2015

HIV Treatment-As-Prevention Research: Taking the Right Road at the Crossroads

Hayes, Richard; Fidler, Sarah; Cori, Anne; Fraser, Christophe; Floyd, Sian; Ayles, Helen; Beyers, Nulda; El-Sadr, Wafaa Mahmoud; HPTN 071 (PopART) Study Team

Despite recent reductions in HIV incidence in several countries in sub-Saharan Africa, incidence still remains at unacceptably high levels [1]. Effective control of the epidemic requires more intensive prevention efforts. Two important approaches to address this goal are “combination prevention” [2], in which a number of partially effective interventions are combined to achieve a substantial reduction in HIV incidence, and “treatment-as-prevention” (TasP), offering antiretroviral therapy (ART) to all HIV-infected adults irrespective of CD4+ T-cell count to prevent onward transmission of HIV [3]. In June 2014, Till Bärnighausen and colleagues [13] presented their views on the implications of the 2013 change in WHO ART guidelines for the TasP studies. Their main conclusions were that as WHO guidelines are implemented [14], it will become unethical to continue the trials because the new guidelines cannot be withheld in control communities; that if the new guidelines are adopted in the control communities, the trials will no longer be adequately powered; and that alternative approaches such as pooling of data or adoption of stepped-wedge study designs should be considered. We believe that the article by Bärnighausen and colleagues contains a number of inaccurate statements that compromise their conclusions. We discuss these issues in relation to the HPTN 071 (PopART) trial that our study team is carrying out in 21 communities in Zambia and South Africa to measure the impact of a combination prevention package, including universal HIV testing and treatment, on population-level HIV incidence [10].