The Worcester HIV Vaccine (WHV)’s Polyvalent DNA/Protein HIV Vaccine (PDPHV) formulation is composed of five DNA vaccine plasmids and four gp120 recombinant proteins. PDPHV is the only vaccine formulation currently under clinical investigation that is covering viral Env antigens from all four major circulating HIV subtypes. The phase 1a clinical study HVTN124 has been completed in a multi-center human study run by the HIV Vaccine Trial Network (HVTN). The initial results have demonstrated that PDPHV is very safe and highly immunogenic in humans which was reported at the HVTN Full Group Meeting in May 2021.
Recently, WHV conducted further analyses to compare the HVTN124 immunogenicity results to published results of other HIV vaccine trials conducted by the HVTN. In a number of immune response assays, the HVTN124 study, especially the DNA prime – protein boost arm, showed either higher response rates or higher magnitude than other reported HVTN studies. The immune response assays used were CD4+ T cell, Env-specific IgG, gp70-V1V2-specific IgG, ADCC (both against gp120-coated target cells or Infectious Molecular Clone (IMC) infected target cells) and neutralizing antibodies response against Tier 1B viruses. More significantly, the HVTN124 formulation elicited high breadth of immune responses against both autologous and heterologous HIV-1 Env antigens. The above data further validated the design of a polyvalent Env formulation delivered by a DNA/protein combination immunization approach to achieve the polyfunctional immune responses with cross-clade breadth.
