At Pontificia Universidad Católica de Chile, a vaccine has been developed to prevent hRSV infection, which is the conventional Bacillus Calmette Guerin (BCG) vaccine modified to recombinantly express the Nucleoprotein of hRSV (rBCG-N-hRSV). This vaccine has proven to be safe and immunogenic in different animal models, both in Chile and the USA. Doses of this vaccine have been manufactured under Current Good Manufacturing Practices (cGMP) conditions in USA, which are suitable to be tested in humans. Due to the unique immunogenic and safety characteristics observed in animal models used to test the efficacy of the rBCG-N-hRSV vaccine prototype, this clinical study will evaluate safety, tolerability and immunogenicity of the immunogenic cGMP formulation in healthy adults.