Clinical safety and efficacy of a powdered Hepatitis B nucleic acid vaccine delivered to the epidermis by a commercial prototype device.

This clinical delivery system bridging study evaluated the performance of a single-use disposable, commercial prototype device (designated ND 5.5) for particle-mediated epidermal delivery (PMED) of a nucleic acid vaccine against Hepatitis B virus (HBV). Healthy adults, previously immunized with licensed HBV vaccine, received a single boost vaccination of HBV nucleic acid vaccine administered by ND 5.5 or XR-1, the clinical research device used in previous clinical trials. Similar increases in anti-HBV surface antigen serum antibody titers and cell-mediated immune responses were produced by ND 5.5 and XR-1 when delivering comparable effective doses of the vaccine. The overall intensity of the immune response was lower in those subjects vaccinated with two, rather than 4 administrations of vaccine delivered by ND 5.5. Skin reactions at sites of vaccine administration were equivalent with both devices. This is the first clinical demonstration of the safe and effective PMED of a nucleic acid vaccine with the ND 5.5 device.