title: Chasing Jenner's vaccine: revisiting cowpox virus classification.
abstract: Cowpox virus (CPXV) is described as the source of the first vaccine used to prevent the onset and spread of an infectious disease. It is one of the earliest described members of the genus Orthopoxvirus, which includes the viruses that cause smallpox and monkeypox in humans. Both the historic and current literature describe "cowpox" as a disease with a single etiologic agent. Genotypic data presented herein indicate that CPXV is not a single species, but a composite of several (up to 5) species that can infect cows, humans, and other animals. The practice of naming agents after the host in which the resultant disease manifests obfuscates the true taxonomic relationships of "cowpox" isolates. These data support the elevation of as many as four new species within the traditional "cowpox" group and suggest that both wild and modern vaccine strains of Vaccinia virus are most closely related to CPXV of continental Europe rather than the United Kingdom, the homeland of the vaccine.
authors.affiliation: Poxvirus and Rabies Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America. DCarroll@cdc.gov
authors.forename: Darin S
authors.initials: DS
authors.lastname: Carroll
authors.forename: Ginny L
authors.initials: GL
authors.lastname: Emerson
authors.forename: Yu
authors.initials: Y
authors.lastname: Li
authors.forename: Scott
authors.initials: S
authors.lastname: Sammons
authors.forename: Victoria
authors.initials: V
authors.lastname: Olson
authors.forename: Michael
authors.initials: M
authors.lastname: Frace
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nakazawa
authors.forename: Claus Peter
authors.initials: CP
authors.lastname: Czerny
authors.forename: Morten
authors.initials: M
authors.lastname: Tryland
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kolodziejek
authors.forename: Norbert
authors.initials: N
authors.lastname: Nowotny
authors.forename: Melissa
authors.initials: M
authors.lastname: Olsen-Rasmussen
authors.forename: Marina
authors.initials: M
authors.lastname: Khristova
authors.forename: Dhwani
authors.initials: D
authors.lastname: Govil
authors.forename: Kevin
authors.initials: K
authors.lastname: Karem
authors.forename: Inger K
authors.initials: IK
authors.lastname: Damon
authors.forename: Hermann
authors.initials: H
authors.lastname: Meyer
mesh_terms: D000818:Animals; D016000:Cluster Analysis; D015608:Cowpox virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D016679:Genome, Viral / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D014764:Viral Proteins / Q000235:genetics
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins