Five out of 32 patients who received very early and prolonged antiretroviral therapy displayed an unusual, sustained immunovirological control after treatment discontinuation (mean duration: 77 months). These 'post-treatment controllers' did not have the genetic characteristics of spontaneous 'elite' controllers, although they shared very low and stable level of viral reservoir. Treatment may have dramatically decreased this reservoir and preserved potent HIV-specific immunologic responses, inducing a new balance between the virus and the host's immune system in these patients.