(LE3) Practical Immunology Flashcards
(54 cards)
What are your two types of immunity?
Acquired
Innate (genetic factors)
- mutations or selective advantage
What are the two types of acquired immunity?
Active (own antibodies)
- memory (long-lived)
Passive (ready-made antibodies)
- temporary
- no memory component
What are two types of active immunity?
Natural - exposure to infectious agent
Artificial - immunization
What are two types of passive immunity?
Natural (maternal antibodies)
- e.g. placenta and breast milk
Artificial (antibodies from other sources)
- e.g. horse serum for rattlesnake bites
What is a vaccine?
suspension of microbes or microbial Ag that induce immunity in host without causing disease
What are the types of whole-cell vaccines?
Inactivated (killed)
Attenuated (alive, weakened)
What are the types of acellular vaccines?
Toxoid (inactivated toxin)
Recombinant Subunit (genetically engineered)
Conjugated (Polysaccharide Ag + Toxoid)
- Weak antigen (weak memory), so combined with Toxoid
- e.g. TdaP
What are examples of a live attenuated vaccine?
Oral Polio vaccine
Measles
Smallpox
What are examples of an inactivated vaccine?
Inactivated Polio Vaccine (IPV)
What are examples of subunit (purified antigen) vaccines?
Haemophilus influenzae type B (Hib)
Hepatitis B
What are examples of toxoid vaccines?
Tetanus toxoid
Diphtheria toxoid
How do the effectiveness and safety of inactivated vaccines compare to attenuated ones?
Inactivated: may damage the Ag and have poor efficacy
Attenuated: have the possibility of conversion back to virulent form (reversion)
How do the two forms of Polio vaccines compare?
IPV (injectable)
- Dr. Salk
- really safe
- 60-70% effective
OPV (oral)
- Dr. Sabin
- Really safe
- > 90% effective
- Reversion. 1/500k children
Both combined to increase safety and efficacy. IPV first, then OPV
What other factors are considered when creating vaccines?
- cost
- shelf life
- strains of pathogen covered (e.g. flu, HPV and covid)
What must be true for a disease to be a candidate for eradication?
Diseases with human-only reservoirs: Polio, Measles, Mumps, Rubella, Smallpox (1980)
What is serology?
Use of a patient’s blood for diagnostic tests (plasma minus clotting factors)
- might detect Ab in serum
- might detect Ag in serum
What are the limitations of serology?
- Ab not produced right away (false negative)
- can’t distinguish between current and past infection or vaccination
- intracellular Ag won’t be detected
How do agglutination reaction diagnostic tests work?
- use cells and particles covered in specific Ag
- add patient’s serum which may or may not have Ab to those Ag
Ab present in serum = agglutination (pos)
Ab not present in serum = no agglutination (neg)
Based on this test, what is this patient’s blood type? What antibodies do they have? Who can they receive blood from?
AB-positive
no antibodies
Universal acceptor
Based on this test, what is this patient’s blood type? What surface antigens do they have? Who can they receive blood from?
O positive
Rh antigen
Accept O positive and O negative
What is RPR test used for? How does it work?
Syphilis
- type of agglutination test
- screening test
- looks for reagin (non-specific Ab) antibody in blood
- charcoal beads bind with reagin Ag
How does precipitin test work?
-serum added to bottom of tube
- add solution of antigen
- if Ab present, there will be visible clumping and appear clooudy
How do Fluorescent Ab tests work?
Use fluorescently-tagged antibodies to bind to specific molecules in sample
How do direct and indirect FA testing differ?
Direct FA - detects Ag in sample
Indirect FA - detects Ab in sample
