National Center for Biotechnology Information NCBI NLM MEDLINE humans pubmed abstract nih national institutes of health national library of medicine research support non-u.s. gov't Child Infant preschool Clinical Trial Randomized Controlled Trial Double-Blind Method placebos severity of illness index respiratory syncytial virus infections / immunology respiratory syncytial virus infections / prevention & control* respiratory syncytial viruses / isolation & purification controlled clinical trial cystic fibrosis / complications vaccines viral vaccines / therapeutic use hn protein* viral envelope proteins respiratory syncytial viruses / immunology child nutritional physiological phenomena respiratory syncytial virus infections / complications pmid:8684872 doi:10.1097/00006454-199601000-00006 p a piedra s grace p w hiatt cystic fibrosis / virology* environment respiratory syncytial viruses / chemistry vaccination* synthetic / adverse effects synthetic / immunology synthetic / therapeutic use viral proteins / immunology* viral vaccines / adverse effects viral vaccines / immunology