Vaccination of macaques with long-standing SIVmac251 infection lowers the viral set point after cessation of antiretroviral therapy

Academic Article


  • A cohort of rhesus macaques with long-standing SIVmac251 infection (≥5 mo) was treated with continuous antiretroviral therapy (ART). A group of eight macaques was vaccinated with or without simultaneous administration of low dose IL-2 with the highly attenuated poxvirus vector (NYVAC) vaccine candidate expressing the SIVmac structural gag-pol-env (gpe) genes and a novel chimeric fusion protein derived from the rev-tat-nef (rtn) regulatory genes. Control groups consisted of mock-vaccinated macaques or animals treated only with IL-2. Vaccination significantly expanded both virus-specific CD4+ and CD8+ T cell responses, and IL-2 further increased the vaccine-induced response to an immunodominant Gag epitope. Following antiretroviral treatment interruption, the viral set point was significantly lower in vaccinated than in control macaques for at least 4 consecutive mo, and viral containment was inversely correlated with vaccine-induced, virus-specific CD4+ and CD8+ T cell responses. These data provide the proof of concept that therapeutic vaccination before cessation of ART may be a feasible approach in the clinical management of HIV-1 infection.
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    Digital Object Identifier (doi)

    Author List

  • Tryniszewska E; Nacsa J; Lewis MG; Silvera P; Montefiori D; Venzon D; Hel Z; Parks RW; Moniuszko M; Tartaglia J
  • Start Page

  • 5347
  • End Page

  • 5357
  • Volume

  • 169
  • Issue

  • 9