Lecture 15 - Murooka Flashcards
(54 cards)
What is the main purpose of a vaccine?
To help the immune system long-term in its defense against infections and pathogens.
Briefly describe variolation.
When and where was this practiced?
What was the mortality rate of this practice?
The practice of innoculating a small amount of dried smallpox material from pustules into a child to produce long-lasting protection against re-infection.
Practiced in India and China in the 10th century.
Fatality was approx 3%
Briefly describe Edward Jenner and his role in the vaccination practice.
Edward Jenner found that milkmaids exposed to cowpox were immune to smallpox and proved experimentally that vaccination was scientifically valid and useful.
Briefly describe Louis Pasteur and his role in the vaccination practice.
Louis Pasteur popularized the word vaccine and further developed Jenner’s work with germ theory and attenuation (rabies).
When was smallpox officially eradicated?
1979
Name three major pathogens that are not cooperative in succumbing to vaccination efforts.
Malaria
Tuberculosis
HIV
What are the two modern vaccination strategies?
Active (vaccination) and passive immunity
Describe in brief the basic properties and actions of a vaccine and their theory.
It is a modified microbe, or a component of which, that is able to stimulate the immune system without acting negatively upon it (biologically inactive but immunologically active) which is intended to trick the immune system into producing a pathogen targeted memory B and T cell response so that, once encountered, the body can recognize a pathogen a mount an appropriate response in order to prevent or lessen the disease.
What is the term for the process of stimulating protective adaptive immune responses against microbes?
Vaccination.
Trick question!
You’d better get this one right.
All vaccines have two parts: what are they?
Antigen
Adjuvant
How do many currently used and effective vaccines work against the pathogens?
They induce antibody formation against the pathogens in question.
What are the two protective mechanisms of vaccines which are able to induce antibodies?
How are vaccines able to do this?
- Prevent damage caused by the pathogen - pre-existing antibodies can neutralize the activity of pathogens that would cause damage to the host.
- Prevent secondary infections - antibody affinity, isotype, complement, and phagocyte activation all play a part.
Describe in brief the primary and secondary response of the immune system upon antigen presentation.
Primary response: Ag induces B and/or T cell responses leaving small number of memory cells.
Secondary response: Memory B and T cells rapidly expand compared to primary response resulting in higher titer of Ag specific, high affinity antibodies.
Why would someone receive a booster shot?
It increases B and T cell responses to keep memory cells alive for a particular pathogen.
Briefly describe the isotypes of each antibody involved in primary and secondary responses and the concentration in which they are present.
Primary: Early IgM response and later IgG (and/or IgA) response
Secondary: Rapid and early IgG (and/or IgA) responses
How do polysaccharide vaccines activate the immune system?
How long term do they work?
How can they work better?
PS vaccines are composed of portions of bacteria so they activate B lymphocytes through T cell independent mechanisms via induction of intermediate-affinity IgG antibodies.
No long-term memory generation.
Conjugate vaccines
Briefly describe how vaccines activate T cell-dependent B cell immunity.
Intramuscular vaccines release Ag/Adj into the muscles to stimulate DCs so that they recognize Ag and then carry it to the lymph node to activate the immune system. From there, B cells make plasma and memory cells able to stimulate T cells and create antibody.
How does the T cell-dependent B cell immunity act during secondary challenge via a pathogen/
B memory cells will be stimulated by an Ag + APC which will then clonally expand B cells to produce large amounts of IgG Abs.
What are the parts of an intradermal vaccine?
Protein or peptide
Adjuvant
What is the point of a peptide/antigen in a vaccine?
What is the purpose of adjuvant in a vaccine?
Antigen is taken up by an immature DC and able to present it to T cells.
Adjuvant activates DCs.
How do antibodies prevent/reduce infections?
Binding to enzymatic active sites of toxins/preventing diffusion.
Neutralizing viral replication
Promoting opsonization
Activating complement cascades.
How do CTLs reduce, control, and clear intracellular pathogens?
Directly killing infected cells (perforin/granzyme).
Indirectly killing infected cells through antimicrobial cytokine release.
How do CD4+ T cells reduce, control, and clear pathogens?
Producing IFN gamma, TNF alpha/beta, IL2, and IL3 and supporting differentiation of B cells, CTLs, and macrophages.(th1)
Producing IL4, 5, 13, 6, and 10 (th2)
Against which diseases have vaccinations been the most effective?
Diphtheria H.influenzae Measles Mumps Polio Rubella Smallpox Tetanus Varicella
