Abstract: New preparative approach of dry powder vaccines for mucosal (e.g. nasal) administration for the purpose of human or animal immunization; it requires spraying a vaccine liquid dispersion, previously mixed with a sub-micron particulate adjuvant, onto a solid carrier while blending the mixture, followed by drying in mild conditions; the sub-micron particulate adjuvant is an O/W nanoemulsion stabilized with a polysaccharide. Improved dry powder vaccines are obtained in form of aggregated antigen-carrier particles, whereby the antigen is finely and firmly dispersed within the carrier; once in contact with the mucosal surface, the product quickly dissociates and releases the antigen component.