Monitoring clinical trials of therapeutic vaccines in HIV infection: role of treatment interruption

Purpose of review To outline the rationale for testing therapeutic vaccines in HIV infection and to discuss the ways in which the antiviral activities of these vaccination trials can be evaluated. In the era of highly active antiretroviral therapy, analytical treatment interruption has served as the gold standard to evaluate therapeutic vaccine strategies. Recent findings In the era before the introduction of highly active antiretroviral therapy, therapeutic vaccine trials showed minimal evidence of antiviral activity. It is not clear whether these failures reflect the immune suppressive effects of HIV replication or the inadequacy of early vaccine constructs and strategies. Recent studies have provided some optimism that therapeutic vaccine strategies may be effective in chronic established infection and perhaps even in chronic HIV infection. Approaches to evaluate the activities of candidate therapeutic vaccine strategies in the era of antiretroviral therapy have included analytical treatment interruptions, but recently the safety of this has been called into question. Summary Although analytical treatment interruption remains the current standard for evaluating the antiviral activities of therapeutic immunization strategies in established HIV infection, other methods and strategies may prove useful and should be evaluated.