Lectures 15 & 16 - Vaccines Flashcards
What are phagocytic cells
Neutrophils
Macrophages
Dendritic Cells
What are antigen-presenting cells
Macrophage
Dendritic Cells
B lymphocytes
What are the classes of T cells
Helper T cells
Cytotoxic T cells
Regulator T cells
What are the classes of B cells
Memory B cell
Plasma cell
Define:
vaccine
preparation of immunogenic material used to induce initial immune response
Define:
vaccination
intentional administration of less virulent pathogens to induce an immune response and protect against later exposure
Who practiced vaccination first
Edward Jenner (smallpox vs. cowpox)
antigenically similar viruses, like cowpox and smallpox, are referred to as
host range mutants
How did Edward Jenner’s vaccine work?
introduced less dangerous cowpox which shared surface antigens with smallpox so the immune system was able to identify
What is the main objective of vaccination
induce B and T lymphocytes to differentiate and produce antigen-specific components
what is passive immunity
born w/ or acquired via maternal passage
MHC II deals with ______ pathogens
exogenous
MHC I deals with _____ pathogens
endogenous
What causes B cells to proliferate
T helper cells
Disease refers to _______ while infection refers to ________
symptoms; presence
Where does the rapid expansion of B and T cells occur
after 2nd exposure
For systemic infections, what is preeminent
IgG
For localized infections, what is preeminent
IgA
what does the preeminent role of IgG or IgA do
prevent systemic spread (IgG)
block entry at the mucosal barrier (IgA)
Where are IgG presented to lymphocytes
lymph nodes and spleen
Where is IgA presented to lymphocytes
submucosa sites
describe the direct development of acquired immunity
Plasma cell to antibody to pathogen
describe the indirect development of acquired immunity
plasma cell to antibody to macrophages
What has a higher binding capacity:
IgM or IgA
Why?
IgM because it is a pentamer (5)
Summarize the 12 steps of vaccine-induced immune response
- binding of “pathogen”
- Engulfment
- RNA release
4a. recognition by MHC I receptors intracellularly
4b. Viral replication and expulsion - dendritic cell interaction
- DC stimulates B cell
- B cell produces antibody
- virus neutralization
- MHC II stimulates helper T cell
- cytokine release
- activated T cells
- apoptosis of infected cell
What are memory B cells (what immunoglobulins)
IgG, IgA, IgE
What needs to be considered when discussing:
effectiveness of vaccines
evoke protective immunity at appropriate sites, of appropriate nature, and have adequate duration
What needs to be considered when discussing:
availability of vaccines
cultured in bulk or readily available
What needs to be considered when discussing:
stability of vaccines
storage, stable under extreme climate conditions
What needs to be considered when discussing:
cheapness of vaccines
what developing countries have for monetary resources
What needs to be considered when discussing:
safety of vaccines
eliminate pathogenicity
What are veterinary examples of highly effective virus control
rabies, canine distemper, feline panleukopenia
What are the vaccine-related reasons for vaccine failure
- transport/handling/storage
- dose and admin
- quality
What are the animal/subject-related reasons for vaccine failure
- maternal antibodies
- immunosuppression
- genetic variation
- stress
What are the pathogen-related reasons for vaccine failure
- strain
- a reversal to virulence
Antigenic drift
gradual accumulation of mutations
Antigenic shift
sudden change due to acquisition of one or more novel surface genes
Reassortment
infected cell produces both parental virus and one RNA segment from either strain
T/F: immunological memory is not lost
False - gradual loss
What are the vaccine types
- modified live
- inactivated (killed)
- subunit
- virus-vectored
- gene-deleted
What types of vaccines fall under gene cloning
subunit, virus-vectored, gene-deleted
Examples of modified-live viral vaccines
smallpox, rabies, cold-adapted equine influenza
attenuate
reduce in virulence
cold-adapted vaccines
selection of mutants with growth at low temperatures so there is gained immunity with low virulence
Examples of inactivated vaccines
FIV, canine influenza, rabies
How are inactivated vaccines made
- virus propagated
- inactivated via heat, light, irradiation, formalin
- add adjuvant
adjuvant
chemical that enhances immune response to antigen
Modified live virus vaccines tend to be highly ____, but not always _____
effective; safe
Inactivated virus vaccines tend to be highly ____, but not always _____
safe; effective
How is a recombinant subunit vaccine made
- foreign DNA inserted to the plasmid vector
- introduction of the plasmid to host cell
- selection of cells containing recombinant DNA
Gene-deleted vaccines
delete genes essential in virulence (safe + effective live virus vaccine)
Example of gene-deleted vaccine
herpesvirus vaccines
Virus-vectored vaccines
protective antigen inserted into nonvirulent virus genome and then inoculated in host
Example of virus-vector vaccines
adenoviruses, rhabdoviruses
mRNA vaccines
prompt the body’s own cells to make a protein fragment found in the pathogen
What are the 5 big steps in mRNA vaccine
- mRNA constructs
- delivery
- expression
- presentation
- immune response
What are the routes of vaccine administration
Parenteral - IM, SQ
Mucosal - oral, nasal, ocular
Dermal - epidermal and SQ
In-ovo/spray - poultry
What are the properties of adjuvants
- induce local inflammation
- prolong antigen persistence
- steer TH1/2 response
- deliver antigens to MHC classes
