immunology applications final review

Why are vaccines important?

Vaccines are our main defense against viral pathogens and have drastically reduced disease-related mortality alongside sanitation.

What diseases currently lack effective vaccines?

HIV and Plasmodium spp. (malaria).

What is the historical origin of vaccination?

12th century China used variolation; Edward Jenner developed modern vaccination.

What challenges are associated with vaccines?

Storage issues, vaccine-associated risks, high development cost, low profit, and delivery limitations.

What are features of an ideal vaccine?

100% effective and safe, single dose, no transmission, long shelf life, room temperature stable, cheap, and induces herd immunity.

What is active immunization?

Stimulation of humoral and cell-mediated immune responses using antigenic material to induce memory.

How do vaccines mimic infection?

They trigger a primary immune response so that future exposures cause a faster, stronger secondary response.

What is a prophylactic vaccine?

A vaccine administered before exposure to prevent disease (e.g., polio vaccine).

What is a palliative vaccine?

A vaccine used to stimulate the immune system after infection (e.g., cancer or HIV vaccines).

What is an attenuated vaccine?

A live but weakened pathogen that triggers strong CMI and humoral immunity.

What are risks of attenuated vaccines?

Reversion to virulence, risk to immunocompromised and pregnant individuals.

What is an inactivated (killed) vaccine?

A vaccine made from whole microbes killed by chemicals or heat; safer but may require boosters.

What is a whole-agent vaccine?

An inactivated vaccine using the entire deactivated microbe.

What is an adjuvant?

A substance added to vaccines to increase antigenicity and enhance immune response.

What is a toxoid vaccine?

Chemically or thermally modified toxins used to induce immunity (e.g., tetanus, diphtheria).

What is a subunit vaccine?

A vaccine using recombinant DNA to produce pure antigen (e.g., Hepatitis B vaccine).

What is a DNA or mRNA vaccine?

A vaccine using genetic material (e.g., coronavirus mRNA in lipid envelopes).

What are some safety concerns with vaccines?

Mild toxicity (fever, soreness), risk of disease in immunocompromised from live vaccines.

What limits vaccine effectiveness?

Limited strain coverage, non-immunizing diseases, and rapid mutation (e.g., flu virus).

What is passive immunization?

Injection of preformed antibodies to provide temporary protection.

What are problems with passive immunization?

Short-lived immunity, risk of serum sickness, contamination, and unwanted antibody responses.

What is a hybridoma?

A fused plasma cell and myeloma cell that produces monoclonal antibodies.

What are monoclonal antibodies?

Identical, pure antibodies made by hybridomas; used therapeutically (e.g., for COVID-19).

What types of immunity exist?

Natural active (infection), artificial active (vaccination), natural passive (maternal antibodies), artificial passive (injected antibodies).

How is molecular biology used in vaccine development?

Recombinant DNA and genetic engineering allow production of specific, pure antigens and RNA-based vaccines.

What are vaccine antigens?

Microbes, microbial parts, proteins, polysaccharides, or toxins used to elicit an immune response.

What are current difficulties in vaccine development?

Rapid mutation, disease not being immunizing, limited strain coverage, cost, and public health issues.