A novel HIV T helper epitope-based vaccine elicits cytokine-secreting HIV-specific CD4+ T cells in a Phase I clinical trial in HIV-uninfected adults.

A Phase I human vaccine trial of a novel polypeptide vaccine of HIV T helper epitopes (EP-1043) and a DNA vaccine of HIV CTL epitopes was conducted in 84 healthy adult volunteers. The vaccine immunogenicity was assessed by an intracellular cytokine staining assay for IL-2, IL-4, TNF-α and IFN-γ. Sixty eight percent (32/47) of subjects had a positive CD4+ T response after receiving two vaccinations of the polypeptide vaccine. The responding CD4+ T cells made various combinations of IL-2, IL-4, IFN-γ, and TNF-α. The study demonstrated that the EP-1043 vaccine is safe, well-tolerated, and immunogenic.