Workshop R: Primary and acquired immunodeficiencies

Abstract

Immune-based therapies for HIV-disease are increasingly investigated as adjuncts to antiretroviral therapy. Despite the dramatic improvement in life expectancy, reversal of morbidity and delay in disease progression afforded by highly active antiretroviral therapy (HAART), the high rate of treatment failure and toxicity associated with these regimens has spurred efforts to find alternate approaches to therapy. Although cell mediated immunity seems to be important in suppressing the first burst of plasma viremia following primary HIV-infection, key elements of HIV-specific immunity are rapidly lost, except in the rare cases of long-term non-progressors or those individuals treated with HAART at the time of acute infection. HIV viremia itself seems to lead to loss of HIV-specific immunity. When HIV replication is successfully suppressed by HAART, partial immune reconstitution usually occurs, but if it has already waned, HIV-specific immunity usually remains absent. It is in this setting that therapeutic vaccination to restore and boost HIV-specific immunity is most often tested. In this article, we review the published trials of HIV therapeutic vaccines, discuss new concepts in immunopathogenesis of HIV-disease that may affect the goals of therapeutic vaccination, examine strategies and vaccines in development and consider the challenges of clinical trial design for immune-based therapies in the era of HAART.