Glossary of virology

This glossary of virology is a list of definitions of terms and concepts used in the study of virology, particularly in the description of viruses and their actions. Table of contents: .A | .B | .C | .D | .E | .F | .G | .H | .I | .J | .K | .L | .M | .N | .O | .P | .Q | .R | .S | .T | .U | .V | .W | .X | .Y | .Z

Glossary of Virology

• AHL-1 cells – A human cell line used in virology studies, particularly for hepatitis and oncogenic virus research.
• Accessory gene regulator – A quorum sensing system in some bacteria and viruses that modulates gene expression, particularly in pathogenesis.
• Antigenic drift – A process of gradual accumulation of mutations in viral antigens, leading to changes in viral surface proteins and reduced immune recognition.
• Antigenic shift – A sudden, major change in a virus’s genome, especially in influenza viruses, resulting in a novel subtype to which most humans lack immunity.
• Attenuated vaccine – A vaccine created using a weakened form of a virus that is still capable of replication but not causing disease.
• Autogenous vaccines – Vaccines made from pathogens isolated from the same individual or herd for targeted treatment.
• Autoinoculation – The process by which an individual spreads a viral infection to different parts of their body.
• B type inclusion – Cytoplasmic inclusion bodies often found in cells infected with poxviruses.
• BCP-1 cells – A human B-cell line used in studies of Kaposi’s sarcoma-associated herpesvirus and other gammaherpesviruses.
• Baby hamster kidney cell – A widely used mammalian cell line (BHK-21) for culturing animal viruses and vaccine production.
• Baltimore classification – A system that classifies viruses based on their type of genome (DNA or RNA, single- or double-stranded) and replication strategy.
• Branched DNA assay – A signal amplification nucleic acid test used for detecting and quantifying viral RNA or DNA.
• Cap snatching – A mechanism used by some RNA viruses to "steal" 5’ caps from host mRNAs to initiate viral mRNA synthesis.
• Capsid – The protein shell of a virus that encloses its genetic material.
• Capsomere – The subunit of a capsid, formed by protein molecules.
• Cell-based vaccine – A type of vaccine developed using cultured cells instead of fertilized chicken eggs, commonly used for influenza.
• Coinfection – The simultaneous infection of a host by two or more virus strains or different pathogens.
• Common Cold Unit – A former UK-based research facility dedicated to studying respiratory viruses, especially the common cold.
• Cryspovirus – A genus of viruses that infect protozoa like Cryptosporidium.
• DNA vaccine – A vaccine that uses a plasmid containing viral DNA to elicit an immune response.
• DNA virus – A virus that has DNA as its genetic material and replicates using DNA-dependent DNA polymerase.
• DPVweb – A curated database of plant viruses and their properties.
• Decoy cells – Cells in the urine resembling virally infected urothelial cells, typically associated with polyomavirus infection.
• Duck embryo vaccine – A vaccine produced using duck embryos, historically used for rabies and other zoonotic viruses.
• Ecotropism – The tendency of certain viruses to infect only specific species or cell types.
• Embryonated – Refers to fertilized chicken eggs used to culture and propagate viruses, especially for vaccine production.
• Emergent virus – A newly identified virus that has recently appeared in a population or is rapidly increasing in incidence.
• Endogenous viral element – Viral sequences that have integrated into the host genome over evolutionary time.
• Endothelial cell tropism – The preference of certain viruses to infect the endothelial cells lining blood vessels.
• GISAID – The Global Initiative on Sharing All Influenza Data, a platform for sharing genome sequences of flu and emerging viruses like SARS-CoV-2.
• Gain-of-function research – Studies involving the enhancement of viral properties, such as transmissibility or pathogenicity, for scientific purposes.
• Global Virome Project – A collaborative effort to discover and catalog unknown viruses with potential pandemic risk.
• Global Virus Network (GVN) – A coalition of medical virologists working to prevent and control viral diseases through global research.
• Glossary of virology – A compiled list of terms and definitions commonly used in the field of virology.
• Group-specific antigen – Viral antigens specific to a group of viruses, used for diagnosis or vaccine design.
• HIV capsid inhibition – A therapeutic strategy that targets the capsid protein of HIV to inhibit viral replication.
• HIV latency – The ability of Human Immunodeficiency Virus (HIV) to remain dormant in host cells, forming a major barrier to a cure.
• Helper dependent virus – A virus that requires the presence of a helper virus to replicate.
• Helper virus – A virus that assists another defective or satellite virus to complete its replication cycle.
• Heterophile antibody test – A diagnostic test for Epstein-Barr virus using cross-reactive antibodies.
• Host tropism – The specificity of a virus for infecting particular host species or cell types.
• Human Immunodeficiency Virus (HIV) – A retrovirus that causes AIDS by targeting CD4+ T cells in the human immune system.
• Inclusion bodies – Intracellular structures formed during viral replication, often used as markers of infection.
• Integrase – A viral enzyme used by retroviruses to insert their genome into the host DNA.
• Intrastructural help – An immunological phenomenon where preexisting immunity to one viral protein enhances responses to others.
• Intrinsic immunity – Innate defense mechanisms in host cells that restrict viral replication even before adaptive immune responses.
• Laboratory-acquired infection – Infections contracted by lab personnel due to accidental exposure to infectious viruses.
• Leaky scanning – A translational control mechanism where ribosomes bypass the first start codon and initiate translation downstream.
• Live virus reference strain – A well-characterized virus used as a standard in vaccine production or diagnostic testing.
• Lysogenic cycle – A viral life cycle in which the genome is integrated into the host cell’s DNA and replicates passively without immediate destruction.
• Lytic cycle – A viral replication cycle that leads to the production of new viruses and host cell lysis.
• Multiplicity of infection – The ratio of infecting virus particles to target cells in an experimental setting.
• Neurovirology – The study of viruses that affect the nervous system and their interactions with neural cells.
• Nomenclature codes – Standardized rules used to name viruses and virus families as determined by bodies like the ICTV.
• Non-cellular life – Refers to entities like viruses and viroids that do not consist of cells but possess life-like properties.
• Oncovirus – A virus capable of causing cancer in humans or animals, e.g., HPV or EBV.
• Original antigenic sin – The immune system’s tendency to preferentially use memory responses from a first exposure even after exposure to a new strain.
• Orphan virus – A virus identified in the absence of a known associated disease.
• Paleovirology – The study of ancient viruses and their interactions with hosts through the analysis of endogenous viral elements in genomes.
• Passenger virus – A virus detected in a host without evidence of disease or replication.
• Permissive cell – A host cell that allows complete replication of a virus.
• PhEVER – A database of viral and host evolutionary relationships.
• PhagesDB – A database of bacteriophages and related data, commonly used in phage research.
• Phenotype mixing – A process where progeny viruses acquire proteins from a different parental virus without genetic recombination.
• Phycodnaviridae – A family of large dsDNA viruses that infect algae.
• Plant virus – A virus that specifically infects plants, often spread by insect vectors or through mechanical means.
• Plaque-forming unit – A measure of infectious virus particles, defined as one infectious unit that forms a visible plaque on a cell monolayer.
• Pleomorphism (microbiology) – The variability in shape and size among virus particles of the same species.
• Portal:Viruses – A central hub for accessing Wikipedia articles and resources related to virology and viruses.
• Pre-integration complex – A nucleoprotein structure formed by retroviruses after entry, containing viral DNA and enzymes like integrase for integration into the host genome.
• Prophage – A dormant form of a bacteriophage genome integrated into a bacterial chromosome during the lysogenic cycle.
• Provirus – Viral DNA that is integrated into the genome of a host cell, particularly in the context of retroviruses like HIV.
• Pseudodiploid – Describes cells (such as HIV particles) that carry two RNA genomes but replicate like diploids without true recombination.
• Pseudotyping – The process of producing recombinant viral particles that bear surface proteins (envelope) from a different virus, used in gene therapy and vaccine development.
• Q-number – A quality control identifier used in standardized virology tests and publications.
• Quasispecies model – A concept describing viral populations as dynamic, highly diverse groups of mutants around a consensus sequence, particularly in RNA viruses.
• RNA interference – A cellular defense mechanism that degrades viral RNA, used in research and therapy to silence gene expression.
• RNA virus – A virus that uses RNA as its genetic material; includes positive-sense, negative-sense, and double-stranded RNA viruses.
• Reassortment – The exchange of genome segments between different viral strains during coinfection, common in segmented RNA viruses like influenza.
• Recombinant virus – A genetically engineered virus containing genes from multiple sources, used in vaccine design and gene therapy.
• Reporter virus particles – Viruses modified to include a reporter gene, allowing detection of infection or replication by a visible signal.
• Satellite (biology) – A subviral agent that requires a helper virus for replication, often dependent on the capsid proteins of the helper.
• See virion – Refers to the complete infectious viral particle, see virion.
• Sense (molecular biology) – Refers to the orientation of RNA in terms of its coding potential: positive-sense or negative-sense RNA.
• Serial passage – A method of virus attenuation or adaptation by repeatedly infecting new hosts or cell cultures.
• Serratus (virology) – A cloud-based platform for the ultra-fast alignment and classification of RNA viruses in metagenomic data.
• Slow virus – A virus that causes disease after a prolonged incubation period, such as prions or lentiviruses.
• Spike protein – A surface glycoprotein that mediates viral entry by binding to host cell receptors; a key target in SARS-CoV-2 vaccine development.
• Strain (biology) – A genetic variant or subtype of a virus, often with specific phenotypic characteristics.
• Superinfection – Infection by a second virus in a host already infected with another, potentially altering disease outcome.
• Szybalski's rule – A rule stating that in double-stranded DNA, the non-template strand tends to be richer in guanine.
• T-number – A value describing the complexity of icosahedral virus capsid symmetry in terms of triangular facets.
• TRIM5alpha – A host protein that inhibits retroviral replication by blocking uncoating of the viral capsid.
• Temperateness (virology) – Describes viruses capable of entering both lytic and lysogenic cycles.
• The Last Days of Smallpox – A documentary about the final eradication efforts for smallpox, a landmark in virological history.
• Tissue tropism – The preference of a virus for infecting specific tissues or organs within a host.
• Transduction (genetics) – The process by which foreign DNA is introduced into a cell by a bacteriophage.
• Vaccine shedding – The release of vaccine virus from a vaccinated individual, usually associated with live attenuated vaccines.
• Vaccine trial – A clinical study designed to evaluate the safety, efficacy, and immunogenicity of a vaccine candidate.
• Vaccine – A preparation that stimulates the immune system to prevent disease, often containing inactivated or attenuated viruses.
• Variant (biology) – A version of a virus with genetic differences from a reference strain, potentially altering transmissibility or immune response.
• VirCapSeq – A high-throughput method for capturing and sequencing viral genomes from complex samples.
• Viral culture – The process of growing viruses in cell lines or tissues to study replication, pathogenesis, or for vaccine production.
• Viral dynamics – The quantitative study of how viruses replicate, spread, and interact with host immune responses over time.
• Viral entry – The process by which viruses penetrate host cells, involving attachment, fusion, or endocytosis.
• Viral envelope – A lipid bilayer derived from the host membrane, enclosing some viruses and aiding in host cell entry.
• Viral epitranscriptome – Modifications to viral RNA that regulate its stability, translation, or interaction with host defenses.
• Viral eukaryogenesis – The hypothesis that viruses may have played a role in the origin of the eukaryotic cell nucleus.
• Viral evolution – The genetic changes in virus populations over time due to mutation, selection, recombination, and drift.
• Viral interference – The phenomenon where one virus prevents the replication of another virus in the same host cell.
• Viral load – The amount of viral RNA or DNA in a host's body, often used as a marker of infection severity.
• Viral matrix protein – A structural protein located between the capsid and envelope, critical for viral assembly and budding.
• Viral metagenomics – The study of viral diversity and abundance in environmental or clinical samples using genome sequencing.
• Viral neuronal tracing – A method using viruses to map neural circuits by tracing connections between neurons.
• Viral pathogenesis – The process by which viruses cause disease in a host organism.
• Viral phylodynamics – The integration of viral evolution with epidemiological and immunological dynamics.
• Viral plaque – A clear area on a cell monolayer caused by virus-induced cell lysis, used to quantify infectious virus particles.
• Viral protein – Any protein encoded by a virus, often involved in replication, immune evasion, or structural integrity.
• Viral quasispecies – A group of closely related viruses within a host that exist as a mutant cloud, typical of RNA viruses.
• Viral replication – The process by which a virus reproduces inside a host cell, involving genome synthesis and particle assembly.
• Viral shedding – The release of virus particles from an infected host through respiratory droplets, feces, or other means.
• Viral synapse – A structured interface between infected and uninfected cells that facilitates efficient virus transfer.
• Viral tegument – A protein layer between the capsid and envelope in herpesviruses, involved in early infection steps.
• Viral transformation – The process by which viruses cause permanent genetic changes in a host cell, potentially leading to oncogenesis.
• ViralZone – An online database offering curated information on viral families, structure, replication, and classification.
• Viremia – The presence of viruses in the bloodstream, an indicator of systemic infection.
• Virion – The complete, infectious form of a virus, consisting of the genome, capsid, and, in some cases, an envelope.
• Viroinformatics – The application of bioinformatics tools to virology, including genome annotation and vaccine design.
• Virokine – A viral protein that mimics host cytokines, used by viruses to modulate the immune system.
• Virological failure – The inability to suppress or reduce viral load despite treatment, often indicating drug resistance.
• Virological.org – An online forum and repository for open scientific discussion about emerging viral threats and genome data.
• Virology Journal – A peer-reviewed scientific journal covering all aspects of virology.
• Virome – The total collection of viruses in a particular environment or organism.
• Viropexis – A proposed mechanism of virus entry involving direct passage through the host cell membrane.
• Virophysics – An interdisciplinary field applying principles of physics to understand viral assembly, entry, and dynamics.
• Viroplasm – A specialized compartment within infected cells where viral replication and assembly occur.
• Virus crystallisation – The process of purifying and crystallizing virus particles for structural analysis.
• Virus inactivation – The process of destroying a virus’s infectivity using heat, chemicals, or radiation.
• Virus latency – The state where a virus persists in a host cell without actively replicating, but can reactivate later.
• Virus quantification – The measurement of viral concentration using techniques like plaque assay, PCR, or ELISA.
• Virusoid – A type of satellite RNA dependent on a helper virus for replication, often circular and non-coding.
• Von Magnus phenomenon – The production of defective interfering viral particles during high-multiplicity passages.
• Vpx – A viral accessory protein encoded by HIV-2 and some SIVs that counteracts host restriction factors.
• Zygotic induction – The activation of prophage genes in bacteria following conjugation.

See also

• Glossary of biology
• Glossary of genetics
• Glossary of scientific naming
• Introduction to viruses
• List of viruses