Immunology & Immunizations Flashcards

1
Q

Describe the lines of defense of the immune system

A

First: (innate) external skin/mucosal membranes

Second: (innate) antimicrobial proteins, phagocytes, other cells that inhibit spread of invaders & trigger inflammation

Third: adaptive immune system

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2
Q

Describe how the surface barriers protect us against microorganisms

A
  • protective chemicals that inhibit/destroy
  • mucus-coated cilia in the respiratory tract sweep microorganisms from lower respiratory passages
  • organ surfaces participate
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3
Q

Describe the internal defenses of the immune system

A

cells and chemicals
- phagocytes
- NK cells
- inflammatory response (macrophages, mast cells, WBCs, chemicals)
- antimicrobial proteins (interferons)
- fever

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4
Q

Describe phagocytes

A

type of cell that engulfs and absorbs bacteria, small cells, particles

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5
Q

Describe macrophages

A
  • develop from monocytes
  • chief phagocytic cells of the immune system
  • free macrophages wander through tissue space
  • fixed macrophages are permanent residents of some organs
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6
Q

Describe neutrophils

A

become phagocytic upon encountering infectious material in tissues

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7
Q

Describe Natural Killer cells

A
  • large granular lymphocytes
  • 2 types of receptors (inhibitory recognize self, activating recognize stressed/infected cells)
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8
Q

what are the cardinal signs of acute inflammation

A

redness, heat, swelling, pain (sometimes impairment of function)

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9
Q

What are the inflammatory mediators

A
  • histamine
  • blood proteins
  • kinins
  • prostaglandins
  • leukotrienes
  • complement cells

(released by injured tissue, phagocytes, lymphocytes, basophils, mast cells)

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10
Q

Describe the vascular permeability step of the inflammatory process

A

inflammatory chemicals cause vasodilation resulting in hyperemia & increased permeability & edema of local capillaries that produces exudates (proteins, clotting factors, antibodies)

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11
Q

Describe how edema works in the inflammatory response

A
  • results from surge of exudates
  • moves foreign materials into lymphatic vessels
  • delivers clotting proteins to form a scaffold for repair and isolate the area
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12
Q

Describe the main points of th einflammatory response

A
  • triggered when body tissues are injured/infected
  • prevents spread of damaging/infectious agents
  • disposes of cell debris & pathogens
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13
Q

What are the 5 leukocytes

A

Granulocytes (PMNs)
- eosinophils
- neutrophils
- basophils

  • lymphocytes
  • monocytes
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14
Q

What are the 4 steps of phagocyte mobilization

A
  • leukocytosis: release of neutrophils
  • margination: neutrophils cling to capillary walls
  • diapedesis: neutrophils pass through
  • chemotaxis: inflammatory chemicals promote positive chemotaxis of neutrophils
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15
Q

What do complement proteins do

A

major mechanism for destroying foreign substances (viral infection)
- consist of 30+ blood proteins that circulate in an inactive form

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16
Q

describe an interferon

A

Function
- antiviral
- reduce inflammation
- activate macrophages & mobilize NK cells

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17
Q

Describe a fever

A
  • systemic response to invading microorganisms
  • leukocytes & macrophages exposed to foreign substances secrete pyrogens
  • pyrogens increase the body’s thermostat
  • high fevers can denature enzymes
  • moderate fevers can increase metabolic rate/repair & sequester iron & zinc in the liver
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18
Q

Describe adaptive immunity

A
  • specific, systemic, memory
  • Humoral immunity: antibody mediated (B cells)
  • cellular immunity: cell mediated (T cells)
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19
Q

Define an antigen

A
  • toxin or foreign substance that induces an immune response & production of antibodies
  • most are large, complex molecules not normally found in the body
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20
Q

Describe B and T lymphocytes

A

cells of the adaptive immune system

  • B (humoral): responsible for creation of antibodies once an antigen provokes a humoral response, mature in red bone marrow
  • T (cell-mediated): proliferate & differentiate into effector cells of immunity & helper cells for antibody response by secreting cytokines, mature in thymus, mature = immunocompetence & self-tolerance

recognize and bind to antigens, communicate with each other to mount a specific immune response to destroy non-self substances

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21
Q

Describe a primary immune response

A
  • occurs on first exposure to an antigen
  • lag period of 3-6 days
  • peak levels of plasma Ab reached in 10 days
  • Ab levels slowly decline
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22
Q

Describe a secondary immune response

A
  • occurs on re-exposure to an Ag
  • sensitized memory cells respond within hours
  • Ab levels peak in 2-3 days at much higher levels than primary response
  • Abs bind with greater affinity
  • Ab level can remain high for weeks/months
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23
Q

Describe active humoral immunity

A

When B cells encounter Ags & produce specific Abs against them

Two types
- Naturally acquired: response to bacterial/viral infection
- Artificially acquired: response to a vaccine of dead/attenuated pathogens

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24
Q

Describe vaccines roles in active humoral immunity

A
  • spare us the sxs of a primary response
  • provide Ag determinants that are immunogenic and reactive
  • target only one type of helper T cell so they don’t fully establish cellular immunological memory
25
Q

Describe passive humoral immunity

A

**B cells not challenged by Abs & immunological memory not occurring*

Two types
- naturally acquired: Abs delivered to fetus via placenta or infant through milk
- artificially acquired: injection of serum such as gamma globulin which provides immediate protection but ends when Abs naturally degrade in the body

26
Q

Flip this card for a nice lil reminder on active vs passive humoral immunity

A
27
Q

Describe antibodies

A
  • immunoglobulins (gamma globulin portion of blood)
  • proteins secreted by plasma cells
  • capable of binding specifically with Ag detected by B cells
28
Q

Describe the cell-mediated immune response

A
  • T cells provide defense against intracellular Ags
  • Types of T cells: Helper T (TH), Cytotoxic T (TC)
  • Others (Regulatory T cells - TREG, memory T cells)
29
Q

Describe the difference between humoral and cell-mediated immune responses

A

HUMORAL
- B cells produce Abs as a simple form of ammunition
- targets: bacterial, molecules in extracellular fluid

CELL-MEDIATED
- T cells recognize & respond to processed fragments of Ags displaced on surface of body cells
- targets: infected body cells, abnormal/cancerous cells, cells of infused/transplanted foreign tissue

30
Q

Describe the role of helper T cells

A
  • central role in adaptive immune response
  • help activate and induce T & B cell proliferation
  • activate macrophages & recruitment o fother immune cells

without TH there is no immune response

31
Q

Describe the role of cytotoxic T cells

A

directly attack & kill other cells

activated Tc cells circulate in blood & lymph in search of body cells displaying the Ag they recognize

Targets:
- virus-infected cells
- cells with intracellular bacteria/parasites
- cancer cells
- foreign cells

32
Q

What are the 2 types of immunization processes

A

active vs passive

33
Q

Describe the active immunization process

A
  • used to simulate the body’s natural defense mechanisms
  • contains non-infectious fragments of bacteria/virus OR a toxin produced by that organism that has been modified to a toxoid

immune system responds by producing Abs and other protective substances

34
Q

Describe the immune response to an active immunization process

A

produces a primary immune response through…
- B cell proliferation
- Ab response
- T-cell sensitization

Subsequent exposure results in a secondary response (increased proliferation of B cells & formation of Abs, protects person from developing disease)

may require boosters to sustain protection

35
Q

Describe live-attenuated active vaccines

A
  • live microbes that are weakened
  • elicit strong cellular & Ab response often conferring lifelong immunity with 1-2 doses
  • contraindicated in those with compromised immune systems

Ex. polio, measles, yellow fever, flumist, zoster

36
Q

List the types of active vaccines

A
  • live-attenuated
  • inactivated
  • subunit/recombinant
  • conjugate
  • toxoid
  • mRNA
  • recombinant vector
37
Q

Describe inactivated active vaccines

A
  • killing the disease-causing microbe with chemicals, heat, radiation
  • more stable/safer than live vaccines (dead microbe can’t mutate back to disease-causing state)
  • weaker than live vaccines therefore require more in a series or boosters

Ex. IPV, Hep A, rabies

38
Q

Describe Subunit/Recombinant active vaccines

A
  • contain only the Ag parts of the pathogen
  • difficult & expensive to create

Ex. Flu shot, pertussis, HPV, Hep B

39
Q

Describe conjugate active vaccines

A

Made using pieces from the coats of bacteria plus a carrier protein

Ex. pneumococcal

40
Q

Describe toxoid vaccines

A
  • protein-based toxin rendered harmless (toxoid) & used as the Ag in the vaccine to elicit immunity
  • used for bacteria specifically
  • may require several doses

Ex. diphtheria, tetanus

41
Q

Describe mRNA active vaccines

A

work by teaching our cells to make a harmless piece of a spike protein which is found on the surface of viruses

Ex. COVID

42
Q

Describe recombinant vector active vaccines

A

use an attenuated virus or bacterium to introduce microbial DNA to cells of the body (still in development)

43
Q

Describe the passive immunization process

A

Abs against a specific infectious organism given directly rather than the body creating them

Sources of Abs
- animal serum from immune source
- pooled human immune globulin
- hyperimmune globulin from people known to have Abs to a specific disease
- Ab-producing cells grown in a lab

44
Q

Describe the uses for passive immunization

A
  • inadequate immune responses
  • infection prior to vaccination
  • to prevent disease when people are likely to get exposed prior to completing a vaccine series
  • occasionally used for healthcare workers, pregnant women, international travelers

(passive immunization lasts only for a few days/weeks until the body eliminates the injected Abs)

Ex. Hep A&B, tetanus, varicella

45
Q

Describe the absolute contraindications to vaccines

A
  • serious allergic reaction to a vaccine or one of its components
  • live vaccines should not be used in those with: weakened immune system/immunosuppressed, pregnancy, some neuro disorders like guillain barre
  • individual per vaccine
46
Q

Describe some of the relative contraindications to vaccines

A
  • recurrent/mild illness
  • current/recent abx use
  • previous mild/moderate local tenderness, redness, swelling, fever after any vaccine
  • previous hx of allergy to specific vaccine contents
  • fam hx of adverse reactions to immunizations
47
Q

What are the things reported in adverse event reporting

A

to the US DHHS
- anaphylaxis/anaphylactic shock within 7 days of a vaccine
- encephalopathy, encephalitis, seizures
- any sequelae
- serious/unusual events
- side effects listed as contraindications to future vaccination on the package insert

48
Q

Describe herd immunity

A
49
Q

What diseases does strep pneumoniae cause

A
  • pneumonia
  • otitis media
  • meningitis
  • bacteremia in peds, elderly, immunocompromised

leading infectious cause of pneumonia related death in kids worldwide

  • rise in resistant pneumococcal strains = urgent need for vaccination
50
Q

What are the immunologic considerations of haemophilus influenzae B

A
  • gram neg anaerobe
  • opportunistic pathogen (lives in host without causing disease until the right opportunity
  • decreased vaccine rates have led to an increase in pneumonia, meningitis, and epiglottitis
51
Q

What are the immunologic considerations for pertussis

A

aka whooping cough
- highly contagious respiratory disease
- caused by bordatella pertussis
- uncontrollable, violent barking cough
- molecular changes to b. pertussis as well as new vaccine mechanism contributing to resurgence/less protective time
- given in Tdap/Dtap vaccine (diphtheria, tetanus, & pertussis)

52
Q

What are the immunologic considerations for Tetanus

A
  • clostridium tetani
  • found in soil, dust, manure, enter through breaks in skin
  • uncommon in the US
  • sxs: jaw cramping, sudden involuntary muscle spasm, GI issues, trouble swallowing, seizures, severe HA, fever, sweating, unstable BP and HR
53
Q

What are the immunologic considerations for diphtheria

A
  • caused by cornybacterium diphtheriae
  • person to person spread (respiratory droplets)
  • thick covering in back of throat leading to difficulty breathing, heart failure, paralysis, death
54
Q

What are the immunologic considerations for meningiococcemia

A
  • neisseria meningitides
  • responsible for bacterial meningitis & sepsis
  • spread person to person through droplets
  • vaccination rates reduced disease and epidemics worldwide
55
Q

Describe the immunologic considerations for diarrhea

A
  • multiple etiologies: rotavirus, shigella, enterotoxogenics, e coli, campylobacter, etc
  • spread through water, food, utensils, hands, flies
  • death d/t dehydration, electrolyte imbalance
56
Q

Describe the immunologic considerations for rotavirus

A
  • most common cause of severe diarrheal disease in young children
  • 2 oral, live, attenuated vaccines available internationally (safe & effective, must be given before 8 months old)
57
Q

What are the immunologic considerations for measles

A
  • viral
  • isolated & extracted measles strain from a sick person’s blood in the 1950s to create the first vaccine in the 1960s: Edmonston-B
  • once dose of measles vaccine is 93% effective in preventing if exposed, 2 doses are 97% effective
58
Q

What are the considerations for immunizations in pregnancy

A
  • protect both mother and baby
  • can provide passive protection against infections acquired independently after birth
  • ideally immunized before conception but can be given during pregnancy especially if: high risk exposure, tarotogenic infection, immunizating agent unlikely to cause harm, effectiveness