Reduced viral burden amongst high responder patients following HIV-1 p24 peptide-based therapeutic immunization

We have previously shown that HIV p24-like peptides (Vacc-4x) via activation of skin dendritic cells induced immune responses in 90% of HIV patients on highly active antiretroviral treatment (HAART). These patients (n = 38) were here subjected to a final 14-week interruption of HAART. Patients with the highest delayed type hypersensitivity (DTH) responses to Vacc-4x-peptides before treatment interruption tended to achieve lower actual HIV RNA levels at the end of the study compared to Vacc-4x DTH low-responders (p = 0.08) and significantly so in terms of viral loads relative to their individual pre-HAART HIV RNA set-points (p = 0.04). CD4+ lymphocyte counts were maintained only among DTH high responders but decreased in the other patients during recurrent viremia (p ≤ 0.02). No other pre-study differences in HIV history or p24-responses were found.