powder for reconstitution with water a ready to feed liquid or a concentrated liquid respiratory viruses to which the invention is applicable include respiratory syncytial virus adenovirus parainfluenza virus and influenza virus studies will be undertaken to determine the impact of feeding neutralizing antibodies against human respiratory syncytial virus hrsv induced pulmonary infection in animals objectives of the studies include identification of an animal model for nasal challenge with hrsv in order to evaluate the influence of dietary feeding on hrsv pulmonary infection and determination whether feeding hrsv neutralizing antibody and or other neutralizing compounds can prevent or mitigate pulmonary infection in the animal following nasal challenge with hrsv a positive outcome with an animal model will eventually permit clinical evaluation of a liquid product enhanced with an hrsv neutralizing compound animals and diet thirty day old inbred cotton rats sigmodon fulviventer free of serum neutralizing antibody against human respiratory syncytial virus hrsv will be used the rats are to be fed a basal liquid diet consisting of infant formula for two days before experiments begin one day before intranasal inoculation of virus the experimental diets will be provided food intake and body weight change are to be monitored daily upon completion of the study all rats will be killed by carbon dioxide asphyxiation and nasal and lung tissue will be removed for analysis virus the virus to be used is human respiratory syncytial virus subgroup a2 hrsv long the virus will be prepared by infecting monolayers of hep 2 cells which will be grown until the monolayers show approximately 9 syncytia formation the.