Medical Interventions Viral Infections

viral characteristics of life

reproduce and adapt to their environment

differences between viruses and cells

cells have organelles and cytoplasm and don’t need a host to reproduce

capsid

protein shell encasing viral genetic material

DNA or RNA

viral nucleic acid cores

surface markers

match to receptor sites on cells

antigens

surface markers that allow a virus to enter a cell

lytic cycle

rapid infection; viral genetic material doesn’t integrate into the host cell; causes the host cell to burst

lysogenic cycle

long period infection; genetic material integrates into the host cell; no lysis of host cell

lysis

when a cell bursts, releasing more virus (in a viral infection)

ELISA

enzyme-linked immunosorbent assay

enzyme

produces a color change if the antigen-primary-secondary-antibody complex is present

primary antibody

an antibody that specifically binds to the target antigen in an immunoassay.

secondary antibody

an antibody that binds to the primary antibody-antigen complex in an immunoassay

weakened vaccine

a vaccine that contains a live but attenuated form of the virus, stimulating an immune response without causing disease.

inactivated vaccine

a vaccine that uses a killed form of the virus to produce an immune response

recombinant vaccine

a vaccine that uses cells to produce antigens from the virus, prompting an immune response without using live pathogens.

conjugate vaccine

a vaccine that uses part of the sugar coat of the virus to produce an immune response to the sugar coat of the virus rather than the virus itself

toxoid vaccine

a vaccine that uses inactivated toxins to elicit an immune response against the toxin rather than the pathogen.

viral vector vaccine

a vaccine that uses a harmless virus to deliver genetic material from the target virus, prompting an immune response.

mRNA vaccine

a vaccine that uses messenger RNA to instruct cells to produce a protein that triggers an immune response against the virus.

immunofluorescence assay

fluorescently labeled antibodies bind onto the antigen

agglutination

produces visible precipitates when antigens and antibodies bind

microplate

a flat plate used in laboratories to conduct multiple tests simultaneously, often for assays like ELISA.

immunochromatography

rapid immunoassays using cards or dipsticks

microscopy

visually identifies pathogens by physical characteristics using electrons or light

retroviruses

a group of RNA viruses that insert a copy of their genome into the DNA of a host cell, leading to persistent infections.

zoonotic viruses

viruses that are transmitted from animals to humans, often causing emerging infectious diseases.

envelopes

lipid membranes that surround some viruses, aiding in their entry into host cells; often produces when a virus buds from a host cell

adenoviruses

a group of DNA viruses that can cause a range of illnesses, including respiratory infections and conjunctivitis.

herd immunity

when a critical mass of a population is immune to a disease

immunity threshold

the percentage of a population that needs to be immune to a disease in order to stop its spread.

R₀ value

a measure of the contagiousness of an infectious disease, indicating the average number of secondary infections produced by one infected individual in a fully susceptible population.