Type Species

Human herpesvirus 6

(HHV-6)

Distinguishing Features

The nucleotide or predicted amino acid sequences form a distinct lineage within the subfamily and the genomes are smaller than those of members of the other genera within the subfamily (< 200 kbp). The viruses productively infect T lymphocytes. Current members are serologically related.

List of Species Demarcation Criteria in the Genus

See above under “List of Species Demarcation Criteria in the Family“.

List of Species in the Genus

Official virus species names are in italics. Tentative virus species names, alternative names ( ), strains or serotypes are not italicized. Virus names, genome sequence accession numbers [ ], and assigned abbreviations ( ) are:

Species in the Genus

Human herpesvirus 6⁵

[X83413]^*

(HHV-6)

Human herpesvirus 7

[U43400, AF037218]

(HHV-7)

^* The HHV-6 accession number is for the “HHV6A” variant, isolate U1102.

⁵ HHV-6 isolates fall into two groups, HHV-6A and HHV-6B, with distinct molecular and biological properties. A case has been made that these should be regarded as distinct species (Braun, Dominguez and Pellett, 1997).

Tentative Species in the Genus

None reported.

Unassigned Members of the Subfamily Betaherpesvirinae

Caviid herpesvirus 2

(CavHV-2)

(Guinea pig cytomegalovirus)


Human herpesvirus 6⁵	[X83413]^*	(HHV-6)
Human herpesvirus 7	[U43400, AF037218]	(HHV-7)