Abstract
The purpose of this study is to evaluate the safety and immunogenicity of a single dose of the recombinant live-attenuated respiratory syncytial virus (RSV) vaccines, RSV ΔNS2/Δ1313/I1314L, RSV 6120/ΔNS2/1030s, and RSV 276, in RSV-seronegative children 6 to 24 months of age.