Chapter 18: Vaccines & Practical Applications of Immunology – Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering vaccine types, immune responses, diagnostic tests, and key immunological terms from Chapter 18 lecture notes.

Vaccine

A suspension of organisms or their fractions designed to induce immunity by provoking a primary immune response.

Vaccination

The administration of a vaccine; a 'dress rehearsal' that prepares the immune system for future encounters with a pathogen.

Primary Immune Response

The initial, slower production of antibodies and memory cells following first exposure to an antigen.

Secondary Immune Response

The rapid, intense antibody production that occurs upon re-exposure to an antigen via memory cells.

Live Attenuated Vaccine

A vaccine containing weakened pathogens that closely mimic natural infection, producing strong, long-lasting cellular and humoral immunity (e.g., MMR).

Inactivated (Killed) Vaccine

A vaccine composed of heat- or chemically-killed pathogens; safer than live vaccines but usually require booster doses and elicit mainly IgG responses (e.g., Salk polio).

Subunit Vaccine

A vaccine using purified antigenic fragments of a pathogen to stimulate immunity with fewer side effects (e.g., acellular pertussis).

Virus-Like Particle (VLP)

A type of subunit vaccine that resembles an intact virus but lacks genetic material (e.g., HPV vaccine).

Toxoid

An inactivated bacterial toxin used as a vaccine antigen to induce immunity to the toxin rather than the bacterium (e.g., tetanus toxoid).

Conjugated Vaccine

A vaccine created by linking a poor antigen (e.g., bacterial capsule polysaccharide) to a strong protein antigen, enhancing immune response (e.g., Hib-tetanus).

Recombinant Vaccine

A subunit vaccine produced by genetically engineered organisms that express the desired antigen (e.g., recombinant Hepatitis B surface antigen).

Live Recombinant Vector Vaccine

A vaccine using an attenuated bacterium or virus engineered to carry genes from a different pathogen, provoking immunity to the inserted antigens.

DNA (Nucleic-Acid) Vaccine

A vaccine in which naked plasmid DNA encoding an antigen is injected, leading host cells to synthesize the antigen and stimulate both humoral and cellular immunity.

mRNA Vaccine

A vaccine delivering synthetic messenger RNA (in lipid nanoparticles) that is translated into antigenic protein inside host cells (e.g., Pfizer-BioNTech COVID-19).

STARK Acronym

Mnemonic for vaccine types: Subunit, Toxoid, Attenuated Live, Recombinant, Killed.

Adjuvant

A chemical additive that enhances the innate immune response to an antigen; alum (aluminum salts) is the only U.S.-approved adjuvant.

Memory Cell

A long-lived B or T lymphocyte formed after primary exposure that triggers fast secondary responses upon re-infection.

Antitoxin

Preformed antibodies that neutralize a specific toxin (e.g., tetanus antitoxin).

Sensitivity (Diagnostic Test)

The ability of a test to correctly identify individuals who have a disease (true positive rate).

Specificity (Diagnostic Test)

The ability of a test to correctly identify individuals who do not have a disease (true negative rate).

Monoclonal Antibody (Mab)

Uniform, highly specific antibody produced in large quantities from a single hybridoma clone.

Hybridoma

An immortal cell line created by fusing a myeloma cell with an antibody-producing B cell; secretes monoclonal antibodies.

Precipitation Reaction

Interaction of soluble antigens with antibodies forming lattice structures that precipitate, as in the precipitin ring test.

Agglutination Reaction

Clumping of particulate antigens by antibodies, used in blood typing and antibody titer determination.

Antibody Titer

The highest serum dilution that still produces agglutination; indicates antibody concentration.

Hemagglutination

Agglutination of red blood cells by viruses or antibodies.

Hemagglutination-Inhibition Test

Neutralization assay where patient antibodies prevent viral hemagglutination of RBCs, used for viral subtyping.

Neutralization Test

Diagnostic method in which antibodies block the toxic or infectious effects of an exotoxin or virus.

Direct ELISA

Enzyme-linked immunosorbent assay that detects antigen in a patient sample using an enzyme-linked antibody.

Indirect ELISA

ELISA that detects patient antibodies; antigen is bound to plate, patient serum adds specific antibodies, then enzyme-linked anti-Ig detects them.

Western Blot

Technique that separates proteins by SDS-PAGE, transfers them to a membrane, and probes with antibodies to detect specific proteins (e.g., confirmatory HIV test).

Southern Blot

DNA detection method involving restriction digest, gel electrophoresis, transfer to membrane, and hybridization with labeled DNA probe.

Northern Blot

Laboratory method analogous to Southern blotting but used for RNA detection and gene expression analysis.

Polymerase Chain Reaction (PCR)

Molecular technique that amplifies specific DNA sequences exponentially, providing rapid, sensitive pathogen detection.

Nanopatch

Microneedle skin patch delivering dry vaccine formulations directly to abundant antigen-presenting cells without refrigeration.

Variolation

Historical practice of deliberately infecting a person with smallpox material to induce immunity; precursor to vaccination.

Booster Dose

Additional vaccine dose given after the primary series to re-expose the immune system and maintain protective immunity.

Cell-Mediated Immunity

Immune protection involving T cells rather than antibodies; strongly stimulated by live attenuated vaccines.

Humoral Immunity

Immunity mediated by antibodies (IgG, IgM, IgA) produced by B cells.

Alum (Aluminum Salts)

The only FDA-approved adjuvant in the U.S.; enhances immune response by activating Toll-like receptors.

Toll-Like Receptor (TLR)

Pattern-recognition receptor of innate immunity that detects pathogen-associated molecular patterns and is stimulated by adjuvants.

Seroconversion

The change from antibody-negative to antibody-positive status in blood, indicating a recent infection or successful vaccination.

Diagnostic Immunology

Field that uses antigen-antibody interactions to identify pathogens, antibodies, or biomarkers in clinical samples.

Pregnancy Test (hCG Test)

Home diagnostic based on a sandwich ELISA using monoclonal antibodies to detect human chorionic gonadotropin.

Antigen

Any substance that can provoke an immune response by binding specifically to antibodies or T-cell receptors.

Antibody (Immunoglobulin)

Y-shaped protein produced by B cells that binds specifically to antigens to neutralize or mark them for destruction.

Opsonization

The coating of pathogens with antibodies or complement proteins to enhance phagocytosis.

Reversion

Rare event where an attenuated vaccine strain mutates back to a virulent form, potentially causing disease.

Multiple-Combination Vaccine

A single formulation containing antigens for several diseases, reducing the number of injections required.