First in vivo evaluation of particulate nasal dry powder vaccine formulations containing ovalbumin in mice.

In this study three different dry powder vaccine formulations containing the model antigen ovalbumin were evaluated for their immune effects after nasal administration to C57Bl/6 mice in an adoptive cell transfer model. The formulations were chitosan nanoparticles in a mannitol matrix, chitosan microparticles and agarose nanoparticles in a mannitol matrix. Dry powder administration to mice was well tolerated and did not result in any adverse reactions. No translocation of the dry powder formulations to the lung could be detected. The local cellular immune response in the cervical lymph nodes was modest and only for the chitosan microparticles and the agarose nanoparticles was there a significant difference compared to s.c. injection of ovalbumin in alum. No humoral response could be measured after nasal administration. The results provide some evidence that nasal administration of dry powder formulations can stimulate an immune response, but the response was modest. This is probably due to a low antigen dose and low immunogenicity of the formulations. Further studies will aim at enhancing the antigen load and improving adjuvant activity.