DNA vaccination in the skin using microneedles improves protection against influenza

Abstract

In this study, we tested the hypothesis that DNA vaccination in the skin using microneedles improves protective immunity compared to conventional intramuscular (IM) injection of a plasmid DNA vaccine encoding the influenza hemagglutinin (HA). In vivo fluorescence imaging demonstrated the expression of a reporter gene delivered to the skin using a solid microneedle patch coated with plasmid DNA. Vaccination at a low dose (3νg HA DNA) using microneedles generated significantly stronger humoral immune responses and better protective responses post-challenge compared to IM vaccination at either low or high (10νg HA DNA) dose. Vaccination using microneedles at a high (10νg) dose further generated improved post-challenge protection, as measured by survival, recall antibody-secreting cell responses in spleen and bone marrow, and interferon (IFN)-γ cytokine T-cell responses. This study demonstrates that DNA vaccination in the skin using microneedles induces higher humoral and cellular immune responses as well as improves protective immunity compared to conventional IM injection of HA DNA vaccine. © The American Society of Gene & Cell Therapy.