School closure during infectious disease pandemic reduces illness transmission

December 07, 2015

All volunteers have now completed their scheduled vaccinations and follow-up visits to the clinic, and the accumulated data suggest that TriGrid??-mediated ADVAX delivery has a good safety profile, is well-tolerated and acceptable to healthy non-HIV-infected human volunteers. Moreover, immunological analyses performed on blood samples taken from the volunteers reveal that electroporation improved the frequency, magnitude, breadth and duration of the cellular immune responses to HIV antigens encoded by the vaccine.

Specifically, in the TriGrid?? arm of the study, cellular immune responses were detected after two immunizations in 37.5% (3/8) of subjects in the 0.2 mg dosage group, 87.5% (7/8) of subjects in the 1.0 mg dosage group, and 75% (6/8) of subjects in the 4.0 mg dosage group. Notably, a third immunization given to the 4.0 mg dosage cohort by electroporation improved the response rate to 100% (8/8 subjects). By contrast, none of the subjects who received ADVAX intramuscularly generated detectable cellular immune responses.

Increasing the dosage of ADVAX delivered using electroporation also enhanced the breadth of the response. Among the responders in the 0.2 mg dosage group, immune responses were detected against one of the four HIV antigens encoded by the DNA vaccine. In the 1.0 and 4.0 mg cohorts, responses were detected against three of four and four of four of the antigens, respectively. Additional analyses are underway to further characterize the immunological responses.

"This is the first study of electroporation in healthy human volunteers. In broad brushstrokes, these results confirm the enhanced immunogenicity of DNA vaccines delivered by electroporation over standard intramuscular immunization that has been seen in animals. This is a step forward in DNA vaccine development," said Dr. David D. Ho, CEO of ADARC and Irene Diamond Professor at the Rockefeller University, and the Principal Investigator of the trial.