four temperature sensitive ( ts ) mutants of respiratory syncytial ( rs ) virus were evaluated for growth and genetic stability in newborn ferrets . ts-1 , the mutant previously tested in children as a possible live virus vaccine and found to be insufficiently attenuated for the upper respiratory tract , grew in the lungs of newborn ferrets to the same peak titer as wild type rs virus .
C0021289
newborn
C0008059
children