Therapeutic DNA Vaccination of Vertically HIV-Infected Children: Report of the First Pediatric Randomised Trial (PEDVAC)

Abstract

SubjectsTwenty vertically HIV-infected children, 6–16 years of age, with stable viral load control and CD4+ values above 400 cells/mm3.InterventionTen subjects continued their ongoing antiretroviral treatment (ART, Group A) and 10 were immunized with a HIV-DNA vaccine in addition to their previous therapy (ART and vaccine, Group B). The genetic vaccine represented HIV-1 subtypes A, B and C, encoded Env, Rev, Gag and RT and had no additional adjuvant. Immunizations took place at weeks 0, 4 and 12, with a boosting dose at week 36. Monitoring was performed until week 60 and extended to week 96.ResultsSafety data showed good tolerance of the vaccine. Adherence to ART remained high and persistent during the study and did not differ significantly between controls and vaccinees. Neither group experienced either virological failure or a decline of CD4+ counts from baseline. Higher HIV-specific cellular immune responses were noted transiently to Gag but not to other components of the vaccine. Lymphoproliferative responses to a virion antigen HIV-1 MN were higher in the vaccinees than in the controls (p = 0.047), whereas differences in reactivity to clade-specific Gag p24, RT or Env did not reach significance. Compared to baseline, the percentage of HIV-specific CD8+ lymphocytes releasing perforin in the Group B was higher after the vaccination schedule had been completed (p = 0.031). No increased CD8+ perforin levels were observed in control Group A.ConclusionsThe present study demonstrates the feasibility, safety and moderate immunogenicity of genetic vaccination in vertically HIV-infected children, paving the way for amplified immunotherapeutic approaches in the pediatric population.Trial registration clinicaltrialsregister.eu _2007-002359-18 IT

HIV DNA Vaccine: Stepwise Improvements Make a Difference

“…Because DNA vaccination can be repeatedly administered without development of immunity to the vector, repeated cycles of therapeutic vaccination resulted in a great benefit with a further reduction in viremia. Recent therapeutic trials using DNA vaccines showed improved immunogenicity ([ 207 , 208 , 209 , 210 ], for recent review see [ 211 , 212 ]) in agreement with findings of the macaque model. Thus, vaccination with plasmid DNAs has several advantages, including the possibility for repeated administration, and was shown to induce potent, efficacious, and long-lasting immune responses.…”

Contrasting Adult and Infant Immune Responses to HIV Infection and Vaccination

“…The vaccine was well tolerated, and there was no significant deterioration in clinical status, no occurrence of serious opportunistic infections, no evidence of adverse effects on the immune system, and no increase in viral replication in vaccinees. Up to 56% of the (94). Interestingly, vaccinated children developed higher lymphoproliferative responses to gag than did adults immunized with the same vaccine.…”

Novel therapies/hopes for HIV cure in perinatally acquired HIV-positive adolescents

“…Interestingly, increased anti-RT cellular reactivities were seen in some of the children (only seen in a minority of adults inoculated with the same vaccine). Therefore, potentially some children may have a better ability to react with viral rRT proteins than adults (56). Please see table 2.…”