Lecture 7: Vaccines Flashcards
Define immunization.
The process by which a person/animal becomes PROTECTED against a disease.
Define vaccination.
Injection of a killed or weakened infectious agent into a living organism to provide immunity against that pathogen.
What are the two general ways we acquire immunity?
Active and Passive Immunity
What is active immunity? What makes up active immunity?
Develops in response to a vaccine or infection.
Natural active immunity is making antibodies because you contracted a disease.
Artificial active immunity is making antibodies because you got a vaccine for a disease.
What is passive immunity? What makes up passive immunity?
Develops after you receive antibodies from someone/something.
Natural passive immunity is being given antibodies via the mother, such as through breast milk.
Natural artificial immunity is being given antibodies via a medication, such as IVIG.
Why is active immunity better than passive immunity?
Provides immediate antibody production and is LONGER-LASTING.
*Does not provide immediate protection, only immediate antibody production.
Why is immunization important if we can still get sick?
It can cause a disease to be less virulent and less symptomatic.
What is immune globulin?
Made from sera collected from a large # of donors’ Ig, (mostly IgG).
What is the major advantage of passive immunity?
Immediate protection, as active immunity needs to develop.
What is the major disadvantage of passive immunity?
It does not last very long, often only a few weeks.
What are some examples of artificial passive immunity?
For primary immunodeficiences: Purified IgGs pooled from donors.
Passive: monoclonal antibodies, polyclonal antibodies, Fab fragments, monovalent vs polyvalent.
What are specific passive immune globulins?
Toxigenic diseases
Envenomation
Viral infections like Ebola or Rabies
Post exposure prophylaxis
What are some examples of passive immunity treatment?
Post exposure to Hep B Virus:
Perinatal exposure to HBIG and HBV vaccines +
multiple dose HBIG given within 1 week.
Crofab: polyvalent antivenom derived from sheep.
What is herd immunity?
Critical portion of community is immunized, preventing an outbreak from happening or making it near impossible.
What are the 3 things we care about when making a vaccine?
What pathogen we want to vaccinate against
How it infects the human body
The way it damages the human tissues
What is valency?
Number of pathogens/strains a vaccine protects against.
Quadrivalent = 4
monovalent = 1
What is gardasil?
Quadrivalent HPV vaccine.
What defines a live, attenuated vaccine?
Protection against viruses via a LIVING virus that has been weakened/attenuated.
It does not cause SERIOUS disease in healthy immune systems.
Produces a strong response, similar to a wild infection.
Often requires 1-2 doses only.
Note: Must be refrigerated to maintain virus
Who should not get a live, attenuated vaccine?
People with compromised immune systems AND preggo people
What are the examples of live, attenuated vaccines?
MMR, Varicella/Zoster, Influenza (NASAL)
What defines an inactivated vaccine?
Protection against a virus.
Virus is killed via chemicals, heat, or radiation.
SAFER and MORE STABLE
Often require multiple doses and/or boosters.
Why can an inactivated vaccine only produce an immune response?
Because the virus is dead, it cannot actually cause disease.
What are some examples of inactivated vaccines?
Polio, Hep A, Rabies
What defines a toxoid vaccine?
Prevents disease caused by BACTERIAL toxins.
Injection of weakened bacterial toxins, known as toxoids.
The immune system will make antibodies that target the toxoid.
What are some examples of a toxoid vaccine?
Diphtheria, tetanus
What defines a subunit vaccine?
Protection against a virus OR bacteria, as it contains the most immunogenic antigens (aka subunits).
This is designed to lower adverse reactions and usually includes 1-20+ antigens.
What are the two mechanisms we develop subunits from?
Lab grown and broken apart.
Recombinant subunit vaccines: Antigen made via recombinant DNA technology.
Gene coding for the antigenic protein is put into a DIFFERENT virus or yeast cells. When the virus/yeast produces, it makes more of the antigenic protein.
What are some examples of subunit vaccines?
Pertussis, Influenza (injection), Hep B, HPV, Novavax
What defines a conjugate vaccine?
Protection against viruses that have an outer coating of polysaccharides. (It disguises the virus, often making it hidden from an immature immune system)
DOES NOT EXPOSE PERSON TO ANY VIRUS
How does a conjugate vaccine work?
Conjugate vaccines are able to connect/conjugate antigens from the immune system to the outer coating, teaching the immune system to find the hidden viruses.
What are some examples of conjugate vaccines?
Hib (Haemophilus infuenza B), Pneumococcal, Meningococcal
(Aka the coccal vaccines)
What defines a DNA/RNA vaccine?
Uses genetic material of a virus to induce a patient’s cells to produce antigens. Our cells take up that DNA so we can make antigens.
They allow us to be sensitized to the key antigens without exposing ourselves to the whole virus.
Why are DNA/RNA vaccines safe?
They cannot cause disease because they lack the whole microbe’s genetic code.
What are some examples of DNA/RNA Vaccines?
Coronavirus (Pfizer/Moderna), Zika Virus, West Nile Virus
What defines a recombinant vector vaccine?
Similar to a DNA/RNA vaccine, but the genetic material from the virus is injected into an attenuated virus/bacteria first. They function as carriers. We then inject the carrier into ourselves so our immune system can recognize them.
How does a recombinant vector vaccine work?
A carrier virus/bacteria holds the genetic material and makes the antigens, which our immune system will recognize to become sensitized.
What are some examples of recombinant vector vaccines?
Coronavirus (J&J), HIV, Rabies, Measles
How does a recombinant vector vaccine differ from a DNA/RNA vaccine?
Recombinant vector vaccines use the same principle but inject the partial genetic material into a carrier virus/bacteria rather than directing.
What are the purposes of vaccine components/ingredients?
Provide Immunity
Keeping the vaccine safe and long-lasting
Producing the vaccination
What are the primary antigens for a vaccine?
Live, attenuated virus
Killed, whole virus
Acellular/subunit
Toxoids
What are some examples of live, attenuated viruses we use in vaccines?
MMR (mumps, measles, rubella), varicella (chickenpox), influenza
What are some examples of killed whole viruses we use in vaccines?
Influenza, Hep A, Rabies
What are some examples of subunits we use in vaccines?
HPV, Pertussis, Hep B
What are some examples of toxoids we use in vaccines?
Tetanus, Diphtheria
What are adjuvants? What two characteristics of our immune system do they affect?
Chemicals we add to a vaccine so our body has a better immune response.
Improved immune memory
Improved immune response/performance
Working mostly in humoral response
What are some common adjuvants? Example vaccine with adjuvant?
Aluminum salts (Alum)
Emulsions
TLR agonists
FLUVAD (Adjuvanted flu vaccine)
Emulsion via squalene oil (Shark liver)
What are the categories of ancillary ingredients in a vaccine and their purpose?
Residual ingredients: help the virus/bacteria grow or produce the vaccine.
Fixatives: kill/inactivate toxins while we make the vaccine.
Preservatives: prevent contamination.
Antibiotics: Prevent contamination from bacteria.
Stabilizing agents: Keep the vaccine effective post production (aka shelf life stability)
Suspending fluids: Carrier to get the vaccine into the body.
Name some examples of residual ingredients.
Growth media components
Egg protein (this is why people with egg allergies cannot take egg-based vaccines!)
Name some examples of fixatives.
Aldehydes
Name some examples of preservatives.
Thimerosal (ETHYL MERCURY), think ehhh
Note:
Methyl mercury is deadly.
Name some examples of antibiotics used in vaccines.
Neomycin
Polymixin B
Gentamicin
Name some examples of stabilizing agents.
MSG, 2-phenoxyethanol, albumin, gelatin
Name some examples of suspending fluids.
Saline, water
What are the four reasons that a vaccine might need more than one dose?
First dose does NOT provide robust immunity. (Most common in inactivated vaccines)
Initial series helps build immunity, but immunity wears off with time. (usually need a booster)
More than one dose is needed to develop the best immune response (primarily live vaccines)
Yearly doses needed due to antigenic drift (Influenza)
What vaccine typically needs more than one dose? What kind of vaccine is it?
Hib
What vaccine typically needs a booster every 10 years?
DTaP
What vaccine requires more than one dose to optimize the immune response?
MMR
Why is a flu shot annual?
Antigenic drift. The strains of flu vary annually in their antigens, making a single vaccine difficult since they constantly change.
Why do mothers need certain vaccines during pregnancy?
Some vaccines can offer immunity to the fetus as well.
Where do I report adverse events related to vaccines to?
VAERS
Vaccine adverse event reporting system.
Who reviews vaccine schedules and efficacies?
ACIP
Advisory Committee on Immunization Practices
How many clinical phases does a vaccine go through?
3 phases
What does the FDA inspect in regards to vaccines?
Vaccine manufacturing facilities
How do we track vaccines?
Lot numbers.
What was the purpose of the National Childhood Vaccine Injury Act (NCVIA)?
Limits liability of vaccine manufacturers
Created the National Injury Compensation Program
(AKA people who get vaccine injuries get compensated)
What are the 3 main examples of vaccine misinformation?
Autism/MMR Vaccine
HIV Vaccine
Thimerosal and Autism
What was the Wakefield study?
A retracted study concluding that the MMR vaccine lead to autism.
Retracted due to small sample size, manipulated subjects, and conflict of interest
Who was Han?
An Iowa state researcher that manipulated data regarding the HIV vaccine.
What is thimerosal? Why was it controversial?
Thimerosal is the compound that generates ethyl mercury, which is a common preservative in vaccines.
Methyl mercury had been discovered as a neurotoxin around the same time autism awareness appeared, misleading people to think that it was the same mercury in vaccines.
What is Gullain-Barre Syndrome?
An ascending paralysis autoimmune disorder resulting in flaccid paralysis.
Associated with Campylobacter jejunum, the 1976 swine flu epidemic, and upper respiratory infections.
GEE YAHN BAR RAY
Define immunosuppression.
A reduction in the effectiveness of the immune system to respond to foreign substance.
What are the three reasons we purposely cause immunosuppression?
Prevention of organ/transplant rejection.
Treating autoimmune diseases.
Treating non-autoimmune diseases (Allergic asthma)
What are the 4 main types of immunosuppressant medications?
Corticosteroids
Cytotoxic drugs
Immunophilins
Monoclonal antibodies (MABs)
What are corticosteroids? Examples?
Anti-inflammatories that fight inflammation very well by blocking production of inflammatory mediators, inhibiting inflammatory cell migration, and promoting apoptosis of leukocytes.
AKA anti-inflammatory but killing WBCs causes immunosuppression.
Examples: Prednisone, hydrocortisone
What are cytotoxic drugs? Examples?
Drugs that kill proliferating cells/inhibit cell division.
Most commonly used for rheumatoid arthritis (RA).
Examples: Azathioprine, cyclophosphamide, methotrexate
What are immunophilins? Examples?
Inhibit signalling pathways of T cell (and sometimes B cell) activation.
Examples: Cyclosporin A, tacrolimus, rapamycin
What are monoclonal antibodies? Examples?
Antibodies that are specific for one antigen and are produced by B cells that are all clones of a unique parent cell B. They bind to the target antigen. Binding can unintentionally impede the biological process causing the disease.
Examples: anti-TNF-alpha (Humira - RA), anti-tumor antigens, COVID-19 MABS
