A novel dry powder influenza vaccine and intranasal delivery technology: induction of systemic and mucosal immune responses in rats

Intranasal (IN) vaccination represents an attractive non-invasive alternative to needle-based injection and provides superior protection at mucosal surfaces. However, new formulations are needed to improve efficacy and reduce the refrigerated storage and distribution requirements associated with standard liquid vaccines. Here, we describe a powder formulation of whole inactivated influenza virus and a novel IN delivery platform. The powder-formulated vaccine elicited a significant serum antibody response in rats that was at least as strong as that provided by the liquid vaccine administered IN or via intramuscular (IM) injection. Significant nasal IgA responses were also observed solely after IN delivery. This study demonstrates for the first time the generation of potent nasal mucosal and systemic immune responses using an IN delivered influenza vaccine powder and suggests an alternative approach to vaccination against influenza and other infectious diseases.