In 1962, a taxonomy of viruses was introduced by André L Woff, Robert W. Horne and Paul Tournier in accordance with the binary classification of living organisms founded by Carl von Linné. In this taxonomy, analogous to the taxonomy of other living organisms, the following taxa are subdivided:
- Genome group
- Order (...virales)
- Family (...viridae)
- Subfamily (...virinae)
- Genus (...virus)
- Species (disease/..virus).
The defining characteristics for this classification were:
- Nature of the viral genome (DNA or RNA/positive-stranded or negative-stranded/single-stranded or double-stranded).
- Symmetry of the capsid
- Presence of lipid envelope (enveloped virus/naked virus)
- Size of virion and capsid (large viruses/small viruses).
The older Baltimore classification is considered obsolete. This classification was temporarily established based on knowledge of the molecular biology of viruses. It goes back to a proposal made by the Nobel Prize winner David Baltimore in 1971. For everyday medical practice, the differentiation between human pathogens and non-human pathogens is of great practical importance.