title: Déjà vu all over again: Koch's postulates and virology in the 21st century.
authors.forename: John V
authors.initials: JV
authors.lastname: Williams
mesh_terms: D002675:Child, Preschool; D056661:Human bocavirus / Q000302:isolation & purification* / Q000472:pathogenicity*; D006801:Humans; D007223:Infant; D014773:Virology / Q000379:methods*; D014777:Virus Diseases / Q000209:etiology*