Cowpox virus: A species of ORTHOPOXVIRUS that is the etiologic agent of COWPOX. It is closely related to but antigenically different from VACCINIA VIRUS.Cowpox: A mild, eruptive skin disease of milk cows caused by COWPOX VIRUS, with lesions occurring principally on the udder and teats. Human infection may occur while milking an infected animal.Orthopoxvirus: A genus of the family POXVIRIDAE, subfamily CHORDOPOXVIRINAE, comprising many species infecting mammals. Viruses of this genus cause generalized infections and a rash in some hosts. The type species is VACCINIA VIRUS.Poxviridae: A family of double-stranded DNA viruses infecting mammals (including humans), birds and insects. There are two subfamilies: CHORDOPOXVIRINAE, poxviruses of vertebrates, and ENTOMOPOXVIRINAE, poxviruses of insects.Poxviridae Infections: Virus diseases caused by the POXVIRIDAE.Vaccinia virus: The type species of ORTHOPOXVIRUS, related to COWPOX VIRUS, but whose true origin is unknown. It has been used as a live vaccine against SMALLPOX. It is also used as a vector for inserting foreign DNA into animals. Rabbitpox virus is a subspecies of VACCINIA VIRUS.Variola virus: A species of ORTHOPOXVIRUS causing infections in humans. No infections have been reported since 1977 and the virus is now believed to be virtually extinct.Monkeypox virus: A species of ORTHOPOXVIRUS causing an epidemic disease among captive primates.Ectromelia virus: A species of ORTHOPOXVIRUS infecting mice and causing a disease that involves internal organs and produces characteristic skin lesions.Serpins: A family of serine proteinase inhibitors which are similar in amino acid sequence and mechanism of inhibition, but differ in their specificity toward proteolytic enzymes. This family includes alpha 1-antitrypsin, angiotensinogen, ovalbumin, antiplasmin, alpha 1-antichymotrypsin, thyroxine-binding protein, complement 1 inactivators, antithrombin III, heparin cofactor II, plasminogen inactivators, gene Y protein, placental plasminogen activator inhibitor, and barley Z protein. Some members of the serpin family may be substrates rather than inhibitors of SERINE ENDOPEPTIDASES, and some serpins occur in plants where their function is not known.Herpestidae: The family of agile, keen-sighted mongooses of Asia and Africa that feed on RODENTS and SNAKES.Vaccinia: The cutaneous and occasional systemic reactions associated with vaccination using smallpox (variola) vaccine.Viral Proteins: Proteins found in any species of virus.Rodent Diseases: Diseases of rodents of the order RODENTIA. This term includes diseases of Sciuridae (squirrels), Geomyidae (gophers), Heteromyidae (pouched mice), Castoridae (beavers), Cricetidae (rats and mice), Muridae (Old World rats and mice), Erethizontidae (porcupines), and Caviidae (guinea pigs).Arvicolinae: A subfamily of MURIDAE found nearly world-wide and consisting of about 20 genera. Voles, lemmings, and muskrats are members.Laboratory Personnel: Professionals, technicians, and assistants staffing LABORATORIES.Inclusion Bodies, Viral: An area showing altered staining behavior in the nucleus or cytoplasm of a virus-infected cell. Some inclusion bodies represent "virus factories" in which viral nucleic acid or protein is being synthesized; others are merely artifacts of fixation and staining. One example, Negri bodies, are found in the cytoplasm or processes of nerve cells in animals that have died from rabies.Smallpox: An acute, highly contagious, often fatal infectious disease caused by an orthopoxvirus characterized by a biphasic febrile course and distinctive progressive skin eruptions. Vaccination has succeeded in eradicating smallpox worldwide. (Dorland, 28th ed)Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.RNA Viruses: Viruses whose genetic material is RNA.Laboratory Infection: Accidentally acquired infection in laboratory workers.Organophosphonates: Carbon-containing phosphonic acid compounds. Included under this heading are compounds that have carbon bound to either OXYGEN atom or the PHOSPHOROUS atom of the (P=O)O2 structure.Genes, Viral: The functional hereditary units of VIRUSES.DNA Contamination: The presence of DNA from a source foreign to the sample being analysed.Cytosine: A pyrimidine base that is a fundamental unit of nucleic acids.Cercopithecus aethiops: A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Receptors, Virus: Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.Virus Cultivation: Process of growing viruses in live animals, plants, or cultured cells.