Active and Passive Immunization Flashcards
Vaccine Manufacture
- Bacterial Vaccines
- Organism grown in broth culture
- Is inactivated with formaldehyde or phenol
- Bacteria separated by centrifuge
- Resuspended in water or 0.9% NaCl for injection
- Dialysed to purify
Vaccine Manufacture
- Viral Vaccines
- Do not grow on inanimate media
- Require cell cultures (Embryonic Cells, Human Cells, Monkey Cells)
- After growth on culture, virus is separated from host cell
- Purified to reduce hypersensitivity reaction
latrogenic Disease
- What is it
An illness that has resulted from a medical treatment
- Vaccines with live virus can cause the disease if the virus mutates and regains pathogenicity
Inactivated Vaccines
- What is it
Chemicals, Heat, Irradiation are used to kill microorganisms
- Can no longer replicated, not viral anymore
Active Immunization
- What are the different kinds
- Naturally Acquired
- From exposure to infection - Artificially Acquired
- From active immunity (vaccination)
DTP/DTap
Mixture of three vaccines that immunize against
- Diphtheria
- Tetanus
- Acellular Pertussis
Inactivated Vaccines
- Examples
Influenza, Rabies, Polio
Passive Immunization
- What is it
Introduction of antibodies or cells produced by another individual.
- Short lasting
- No formation of immunological memory
Live Vaccines
- Examples
Measles, Mumps, Sabin Polio Vaccine
Non-Traditional mRNA Vaccine
Modified viral mRNA is used to induce viral protein synthesis and immune response by the immune system
Live Vaccines
- Advantages and Disadvantages
Advantages
- Specific and relevant immune response
- Only needs small dose
- Lifelong memory
- Cytotoxic T-Cell induction
Disadvantages
- Can revert into pathogenic form
- Can not be used in immunocompromised
Therapeutic Vaccines
- What is it
Activates Immune System to fight:
- Cancer
- Chronic Viral Infection
- Bacterial Infection
- Neurodegenerative Disease
- Autoimmune Disease
- Organ Transplantation
ISCOMs
- What is it
Immune Stimulating Compounds
1. ISCOMs enclose peptide
2. ISCOM-APC fuse together and inject antigen into cell
Freund’s Complete Adjuvant
- What is it
Suspension of dead mycobacteria in oil and detergent
- Stimulates immune response to weak immunogens (activates macrophages)
- Detergent keeps antigen and oil in suspension
–> Slow release, depot effect
Only used experimentally
mRNA Vaccines
- Process
- Antigen Expression (In APCs)
- DC maturation and migration
- Activation of T(FH) and GC B-Cells
Whole Cell vs Acellular Vaccines
Whole Cells contain the entire inactivated microorganism
Acellular Vaccines contain only parts or subunits of the organism and/or toxin
Live Vaccines
- What is it
Chemical, Heat, Irridation is used to attenuate virus
Can also:
1. Pathogen is isolated and grown in human culture cells
2. Virus is then used to infect monkey cells
3. Virus acquires mutations allowing it to grow in monkey cells
4. When re-introduced into patient the virus can no longer grow well (it is attenuated)
Toxoid Vaccines
- What is it
- Inactivates endotoxins instead of targeting the bacteria
- Antigenicity of the toxin still remain
Not enough to cause an immune response
- Must be combined with adjuvant
What is a Vaccination
Purposeful introduction of an immunogen (antigen) to induce protective immunity against a disease
What vaccines provide the best effects
Live attenuated viruses provide the closest challenge as a natural pathogen to the immune system
- However, can mutate back into pathogenic form
Secondary Exposure
- Memory B and T-Cells initiate rapid response
- IgG antibody dominates
- Antibody (IgG) with greater affinity and greater binding strength produces a larger effect
- Secondary response lasts longer
Aluminum Compounds
- What is it
Aluminum phosphate and hydroxide that enhances immunostimulation and antigen slow delivery
- Pain at site of injection
Main vaccine adjuvant
What are the primary goals of immunizations
To elicit production of neutralizing antibodies and to develop cell mediated immunity
mRNA Vaccine
- How does immune system respond
Infected Dendritic cells process and load viral antigen on MHC class I and MHC class II
CD4 T-Helper Cells (Lymph Node Follicular Helper) recognizes as viral protein antigen as foreign
- Co-ordinates Germinal Centre B-Cell antibody humoral response
CD8 Cytotoxic T-Cells remove virally infected cells
Primary Exposure
- Antigen is processed and presented on CD4 T-Helper Cells
- This process is time consuming (lag phase)
- IgM dominates
- Delay before more Ag-specific IgG (affinity maturation) isotype response
- Downregulation of primary response
- Effector cells cleared
mRNA Vaccine
- Advantages and Disadvantages
Advantages
- Does not use toxic chemicals or cell cultures that can be contaminated
- Short manufacturing time
- Safe vaccine format (mRNA molecule codes for just viral protein antigen, no risk of infection)
Disadvantages
- mRNA is unstable
- Inefficient in vivo delivery
Genetically Engineered Live Attenuated Pathogens
- What is it
Modifying a virus so it is no longer virulent
- Immune system can still recognize virus
- Pathogenic Virus is isolated
- Isolate virulence genes
- Mutate virulence gene OR Delete virulence gene
- Resulting virus is immunogenic and is avirulent.
- Avirulent Virus can be used as vaccine
Adjuvants
- What is it
Insoluble agents that are administered with an antigen to improve its antigenicity
What kind of Vaccine is the Polio Vaccine
First Dose:
- Inactivated Polio Vaccine
Second Dose
- Live Attenuated Polio Vaccine, given after some immunity has built
Active Immunization
- What is it
Stimulation of an immune response using an antigen creating immunological memory
What do self-amplifying mRNA vaccines encode
- Antigen of interest
- Viral replication machinery
- Enables intracellular RNA amplification and lots of intracellular protein expression of antigen
Basically increases expression of virus antigen
Passive Immunization
- What are the different kinds
- Transfer of Antibodies
- Natural: Mother to fetus
- Artificial: Antivenom - Transfer of Cells
Administration method of Vaccines
- Other Delivery Methods
Lipid Micelle Delivery
- Peptide Antigens
Lipid and Polymer
- mRNA Antigens
Transgenic Plants
- Immunogenic proteins that are found in food
Administration method of Vaccines
Intra-Dermal
Sub-cutaneous
Intramuscular
Oral Vaccine
Inactivated Vaccines
- Advantages or Disadvantages
Advantages
- Do not become viral again
- Does not use intact cells
Disadvantages
- Have to repeat administration to get effective potentiation
- No induction of Cytotoxic T-Cells
