Virion

[4] A virion consists of one or more nucleic acid genome molecules (single-stranded or double-stranded RNA or DNA) and coatings (a capsid and possibly a viral envelope).

[5] In the vast majority of viruses, the DNA and RNA components are packed into a protein shell, the capsid.

[3] In many viruses, the virions have icosahedral symmetry, which can be ideally isometric or elongated.

The tail of these viruses serves as an injection device to introduce their own genome into the host cell.

[9][10][clarification needed] Spikes (peplomers) can protrude from the capsid, as in the Coronaviridae, the Tectiviridae, and others.