Priming with a simplified intradermal HIV-1 DNA vaccine regimen followed by boosting with recombinant HIV-1 MVA vaccine is safe and immunogenic: a phase IIa randomized clinical trial.

ABSTRACT:

Background

Intradermal priming with HIV-1 DNA plasmids followed by HIV-1MVA boosting induces strong and broad cellular and humoral immune responses. In our previous HIVIS-03 trial, we used 5 injections with 2 pools of HIV-DNA at separate sites for each priming immunization. The present study explores whether HIV-DNA priming can be simplified by reducing the number of DNA injections and administration of combined versus separated plasmid pools.

Methods

In this phase IIa, randomized trial, priming was performed using 5 injections of HIV-DNA, 1000 μg total dose, (3 Env and 2 Gag encoding plasmids) compared to two "simplified" regimens of 2 injections of HIV-DNA, 600 μg total dose, of Env- and Gag-encoding plasmid pools with each pool either administered separately or combined. HIV-DNA immunizations were given intradermally at weeks 0, 4, and 12. Boosting was performed intramuscularly with 108 pfu HIV-MVA at weeks 30 and 46.

Results

129 healthy Tanzanian participants were enrolled. There were no differences in adverse events between the groups. The proportion of IFN-γ ELISpot responders to Gag and/or Env peptides after the second HIV-MVA boost did not differ significantly between the groups primed with 2 injections of combined HIV-DNA pools, 2 injections with separated pools, and 5 injections with separated pools (90%, 97% and 97%). There were no significant differences in the magnitude of Gag and/or Env IFN-γ ELISpot responses, in CD4+ and CD8+ T cell responses measured as IFN-γ/IL-2 production by intracellular cytokine staining (ICS) or in response rates and median titers for binding antibodies to Env gp160 between study groups.

Conclusions

A simplified intradermal vaccination regimen with 2 injections of a total of 600 μg with combined HIV-DNA plasmids primed cellular responses as efficiently as the standard regimen of 5 injections of a total of 1000 μg with separated plasmid pools after boosting twice with HIV-MVA.

Trial registration

World Health Organization International Clinical Trials Registry Platform PACTR2010050002122368.

SUBMITTER: Munseri PJ 

PROVIDER: S-EPMC4398367 | biostudies-literature |

REPOSITORIES: biostudies-literature