Virology Flashcards
International Committee on Taxonomy of Viruses of the Virology division of the International Union of Microbiological societies responsible for viral taxonomy
ICTV
A characteristic of a virus in which only certain hosts can be infected
Tropism
A virus particle that contains nucleic acid core and protein coat; others have additional lipid envelope
Virion
Either DNA or RNA (Basis of Virus classification); encodes proteins for viral replication
Nucleic acid/ Viral genome
Protein shell or coat that protects the nucleic acid
Capsid
The basic protein building blocks of a coat
Protomer/Structural unit
A nucleic acid genome surrounded by a symmetric protein coat
Nucleocapsid
Repeating symmetrical structural subunits of capsid; forms the viral capsid shape (Icosahedral/Helical/Complex)
Capsomere
A capsid structure that is cubical and have 20 flat sides
Icosahedral
A capsid structure that is spiral in shape
Helical
Composed of lipids responsible for viral entry into the host cell
Envelope
Inserted within the envelope (e.g. hemagglutinin, neuraminidase, or glycoprotein spikes)
Viral proteins
Located between envelope and nucleocapsid; has enzymes that contribute to viral infection
Matrix protein
Composed of glycoprotein that are present in some viruses; acts as virus receptor and facilitates in virus entry to the host cell
Viral spikes/Peplomer
Viruses that do not have envelope (more resistant to environmental factors & disinfectants, usually Fecal-Oral route)
Non-enveloped viruses/Naked
Viruses that have envelope (more sensitive to environmental factors & disinfectants)
Enveloped viruses
Minor changes that occur continuously over time as the virus replicates
Antigenic drift
Major changes that result in novel viral antigens
Antigenic shift
Refers to a single change in a virus’s genome (genetic code)
Mutation
A virus with a genome formed by combining genetic material from different strains or species
Recombinant
A process in which the genomes of two SARS-CoV-2 variants (that have infected a person at the same time) combine during the viral replication process to form a new variant that is different from both parent lineages
Recombination
A viral genome (genetic code) that may contain one or more mutations
Variant
A variant that is under monitoring as it may pose further mutations that could lead to increase transmissibility, disease severity, and reduced treatment effectivity
Variant Being Monitored (VBM)
A variant widely spreading in many places or countries due to mutations in the specific genetic markers associated to receptor binding, reduced neutralization by antibodies generated against previous infection or vaccination
Variant of Interest (VOI)
A variant for which there is evidence of an increase in transmissibility, more severe disease (e.g., increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures
Variant of Concern (VOC)
A variant of high consequence has clear evidence that prevention measures or medical countermeasures have significantly reduced the effectiveness compared to previously circulating variants
Variant of High Consequence (VOHC)
A viral phase in which the virus is in the host cells and is in the resting state instead of replicating continuously
Temperate phage or prophage
A stage of viral replication in which replication and expression of genetic material in the host cell occurs. No after virus replication, the cell lyses, caused by viral phage
Lytic stage
Autoimmune pathogenesis: When pathogenic virus antigens cross-react with the antigens similar to the host tissues and immune reaction begins, over time, leading to impairment of host function
Autoimmune pathogenesis
Transformation/Immortalization: When host cells express specific viral proteins affecting its cell cycle and resulting in dysregulation or uncontrolled cell proliferation
Transformation/Immortalization
Oncogenic virus/Oncovirus: A virus that has the ability to stimulate uncontrolled growth of host cells (e.g. HPV)
Oncogenic virus/Oncovirus
A viral genome (genetic code) that may contain one or more mutations
Variant
A variant that is under monitoring as it may pose further mutations that could lead to increase transmissibility, disease severity, and reduced treatment effectivity
Variant Being Monitored (VBM)
A variant widely spreading in many places or countries due to mutations in the specific genetic markers associated to receptor binding, reduced neutralization by antibodies generated against previous infection or vaccination
Variant of Interest (VOI)
A variant for which there is evidence of an increase in transmissibility, more severe disease (e.g., increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures
Variant of Concern (VOC)
A variant of high consequence has clear evidence that prevention measures or medical countermeasures have significantly reduced the effectiveness compared to previously circulating variants
Variant of High Consequence (VOHC)
A viral phase in which the virus is in the host cells and is in the resting state instead of replicating continuously/Temperate phage or prophage
Lysogenic stage
A stage of viral replication in which replication and expression of genetic material in the host cell occurs. No after virus replication, the cell lyses, caused by viral phage/Lytic stage
Eclipse stage
When pathogenic virus antigens cross-react with the antigens similar to the host tissues and immune reaction begins, over time, leading to impairment of host function
Autoimmune pathogenesis
When host cells express specific viral proteins affecting its cell cycle and resulting in dysregulation or uncontrolled cell proliferation
Transformation/Immortalization
A virus that has the ability to stimulate uncontrolled growth of host cells (e.g. HPV)
Oncogenic virus/Oncovirus
A multinucleated clump of cell from a fusion of infected host cells and additional nearby host cell/Hall of RSV no respiratory virus
Syncytia
The indirect protection from an infectious disease that happens when a population is immune either through vaccination or immunity developed through previous infection
Herd immunity/Population immunity
Virus that only cause disease in animals
Epizootic virus
Viral replication stages: attachment, penetration, uncoating, synthesis, assembly, release (cell lysis by naked virus; budding by enveloped viruses)
Viral replication stages
Adsorption through glycoprotein spikes
Attachment
Virus entry into the host cell
Penetration
Capsid is removed and nucleic acid is released; basis of viral classification
Uncoating
Transcription of nucleic acid and protein synthesis of DNA to RNA (eclipse stage)
Nucleic acid and protein synthesis
Formation of capsid and genome
Assembly
Cell lysis by Naked virus; Budding by Enveloped viruses (gets the host cells’ envelope)
Release
