Vaccine-induced T cells provide partial protection against high-dose rectal SIVmac239 challenge of rhesus macaques

Academic Article


  • Despite enormous efforts by the scientific community, an effective HIV vaccine remains elusive. To further address to what degree T cells in absence of antibodies may protect against simian immunodeficiency virus (SIV) disease progression, rhesus macaques were vaccinated intramuscularly with a chimpanzee-derived Ad vector (AdC) serotype 6 and then boosted intramuscularly with a serologically distinct AdC vector of serotype 7 both expressing Gag of SIVmac239. Animals were subsequently boosted intramuscularly with a modified vaccinia Ankara (MVA) virus expressing Gag and Tat of the homologous SIV before mucosal challenge with a high dose of SIVmac239 given rectally. Whereas vaccinated animals showed only a modest reduction of viral loads, their overall survival was improved, in association with a substantial protection from the loss of CD4 T cells. In addition, the two vaccinated Mamu-A01 macaques controlled viral loads to levels below detection within weeks after challenge. These data strongly suggest that T cells, while unable to affect SIV acquisition upon high-dose rectal infection, can reduce disease progression. Induction of potent T-cell responses should thus remain a component of our efforts to develop an efficacious vaccine to HIV-1. © The American Society of Gene & Cell Therapy.
  • Authors

    Published In

  • Molecular Therapy  Journal
  • Digital Object Identifier (doi)

    Author List

  • Lasaro MO; Haut LH; Zhou X; Xiang Z; Zhou D; Li Y; Giles-Davis W; Li H; Engram JC; Dimenna LJ
  • Start Page

  • 417
  • End Page

  • 426
  • Volume

  • 19
  • Issue

  • 2