Enhanced Memory Responses to Seasonal H1N1 Influenza Vaccination of the Skin with the Use of Vaccine‐Coated Microneedles

Abstract

Background. Morbidity and mortality due to influenza could be reduced by improved vaccination. Methods. To develop a novel skin delivery method that is simple and allows for easy self-administration, we prepared microneedle patches with stabilized influenza vaccine and investigated their protective immune responses. Results. Mice vaccinated with a single microneedle dose of trehalose-stabilized influenza vaccine developed strong antibody responses that were long-lived. Compared with traditional intramuscular vaccination, stabilized microneedle vaccination was superior in inducing protective immunity, as was evidenced by efficient clearance of virus from the lung and enhanced humoral and antibody-secreting cell immune responses after 100% survival from lethal challenge. Vaccine stabilization was found to be important, because mice vaccinated with an unstabilized microneedle vaccine elicited a weaker immunoglobulin G 2a antibody response, compared with the stabilized microneedle vaccine, and were only partially protected against viral challenge. Improved trafficking of dendritic cells to regional lymph nodes as a result of microneedle delivery to the skin might play a role in contributing to improved protective immunity. Conclusions. These findings suggest that vaccination of the skin using a microneedle patch can improve protective efficacy and induce long-term sustained immunogenicity and may also provide a simple method of administration to improve influenza vaccination coverage.