The development of a safe and efficient RSV vaccine for infants in the first six months of life is a public health challenge for reducing the severe burden of respiratory diseases and hospitalizations. Globally, it is estimated that RSV causes > 30 million lower respiratory tract infections each year resulting in >3 million hospitalizations, making it the most common cause of hospitalizations in children under 5 years old. Since the failure of formalin-inactivated virus vaccines, a large array of alternative vaccination strategies (vaccine candidates and routes of administration) has been explored against RSV without providing satisfactory solutions. There are major challenges, unique to RSV, related to the young age of infection, the failure of natural infection to induce immunity that prevent reinfection and the risk of immune-mediated disease exacerbation. However, there are currently nor adequate treatment nor vaccine commercially available. The RSV-NanoViaSkin project aims to develop a pre-clinical proof of concept for an innovative efficient and safe pediatric RSV vaccine able to overcome all the barriers of current RSV vaccination strategies. Several innovations are gathered in the project to develop the epicutaneous RSV pediatric vaccine: 1) an original patented carrier derived from the viral nucleoprotein, produced and purified by the team of VIM-INRA which forms ring-shaped nanostructures (Nring) and is decorated with epitopes from the viral fusion protein (eF), and 2) an original patented epicutaneous delivery system (Viaskin®) loaded according to an innovative process, the electrospray, developed by DBV Technologies. In fact, the expected breakthroughs concern several parts of the project: o Novel immunogenic antigens (N-eF proteins), targeting CTL and neutralizing antibody mediated immunity to RSV, using well characterized immunogenic nanostructures (Nring) based on patented/published pre-clinical results, carried out by VIM-INRA o Innovative way to administer the vaccine: the epicutaneous route of administration using an original adapted technology (Viaskin®) able to overcome the hurdles of interference of maternal antibodies and the immaturity of the immune system. The new technology has the advantage that it does not require any preparation of the skin and adjuvant to facilitate the passage of the antigen through the skin. o An innovative loading process: the Electrospray allows loading of very small amounts of antigen protected from biological/physical degradation. This robust industrial process is already used in the production of cutaneous device. o Validation by preclinical tests of efficiency and safety in animal models adapted to the issues of epicutanous neonatal RSV vaccine (neonate mice, piglet skin, cotton rat, rabbit) This preclinical research will enable to define the clinical development strategy for the first non-invasive and adjuvant-free epicutaneous RSV pediatric vaccine that is able to protect the respiratory tract of newborns and infants against viral infection. The new approach will offer great benefits in terms of ease to use and painlessness compared to other pediatric vaccines in development. The project will associate industrial (DBV Technologies) and academic (VIM-INRA) partners to bring together all the complementary competences needed for the success of the project. The project will be conducted for 30 months. This project is the first step before entering in a clinical development process. The results will enable us to enter in the first-in-man clinical phase.