Methods of inducing a safe immune response against respiratory syncytial virus (RSV) in a human subject in need thereof, including administering to the subject a composition including recombinant adenovirus including a nucleic acid encoding an RSV Fusion (F) protein including the amino acid sequence of SEQ ID NO: 1, and a pharmaceutically acceptable carrier, in a total dose of from about 1×1010 to about 2×1011 viral particles (vp), are described.