Definition of virion in US English:



  • The complete, infective form of a virus outside a host cell, with a core of RNA or DNA and a capsid.

    • ‘It is probable that movement of poliovirions occurs through the interaction of the virions with the host cell actin similar to the mechanisms seen in some bacterial infections 10-12.’
    • ‘A US research team examined the possibility that normal human oral keratinocytes might be directly infected by HIV or might convey infectious HIV virions to adjacent leucocytes.’
    • ‘The humoral arm produces virus-neutralizing antibodies that, when fully effective, completely prevent virions from infecting new host cells.’
    • ‘At the center of the virion is a protein capsid containing two identical, single strands of genomic RNA, plus essential reverse transcriptase enzymes, as well as some accessory molecules.’
    • ‘However, the tubes may contain multiple virions, or capsids, like peas in a pod, or the linear arrangement of spores in neurospora filaments.’


1950s: from virus + -on.