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.