Immunoprophylaxis

Question 1

ways of acquiring immunity

Answer 1

natural infection and vaccination

Question 2

innate and adaptive effector mechanisms

Answer 2

read

Question 3

effector antibodies

Answer 3

• bacteria toxins: neutralization
• bacteria in extracellular space: opsonization
• bacteria in plasma: complement activation -> lysis and phagocytosis

Question 4

t-cell activation steps

Answer 4

1. signal recognition: apc + mhc presents to t cell
2. costimulation: b7 and cd 40 from apc, cd40L and cd28 from t cell
3. proliferation

Question 5

effector t cells

Answer 5

cd4 (th1 and th2) or cd8 (cytotoxic t cells)

Question 6

functions of cd4 and cd8 cells

Answer 6

cd4: stimulate tregs, macrophages, b cells, and differentiation of cytotoxic t cells; promote migration and activation
cd8: induce target cells to die, produce protein in lytic granules, release cytokines

Question 7

protein lytic granules produced by cd8 t cells

Answer 7

• perforin: polymerizes to form pore on target membrane
• granzymes: activate apoptosis in cytoplasm of target cell
• granulysin: induces apoptosis

Question 8

primary antibody response to vaccine

Answer 8

• “priming”
• bridging of apcs
• days to weeks
• forms memory cell population for months, years, or life

Question 9

secondary antibody response to vaccine

Answer 9

• “boosting”

- memory cells can make greater and more rapid response

Question 10

primary vs secondary response

Answer 10

read

Question 11

types of vaccines

Answer 11

• live attenuated
• inactivated
• subunit
• toxoid

Question 12

principles of live attenuated vaccines

Answer 12

• antigens are live and replication competent, but reduced virulence (similar to natural infection)
• unpredictable + safety and stability concerns

Question 13

principles of inactivated vaccines

Answer 13

• dead or inactivated viruses
• may not always induce immune response, may not be long lived
• need several doses
• no risk inducing disease, more stable than lav

Question 14

principles of reassortant vaccines

Answer 14

• at least 2 different strains of same pathogen

Question 15

principles of subunit vaccines

Answer 15

• contain antigenic parts of pathogen
• con: needs exact details on which components to use
• no guarantee immune memory will be formed
• very safe

Question 16

principles of protein based subunit vaccine

Answer 16

• uses specific isolatted protein of pathogen
• con: can be denatured
• acellular pertussis vaccine and hep b vaccine

Question 17

principles of polysaccharide vaccine

Answer 17

• creates response against molecules in pathogen’s capsule
• small, not very immunogenic
• ineffective in infants and young children
• only short term immunity

Question 18

principles of conjugate subunit vaccine

Answer 18

• create a response against molecules in a pathogen’s capsule
• long term protective response
• can prevent common bacterial infections
• hib and pneumococcal

Question 19

polysaccharide vs polysaccharide conjugate vaccines

Answer 19

read

Question 20

principles of toxoid vaccines

Answer 20

• based on toxin of bacteria (ex. tetanus or diptheria)
• harmless protein-based toxin as antigen
• aluminum or calcium salts = increase immune response
• no possibility of reversion and stable

Question 21

adverse events following immunization

Answer 21

• vaccine product related reaction (inherent property)
• vaccine quality defect related reaction (+ administration device)
• immunization error-related reaction (handling, prescribing, or administration = PREVENTABLE)
• immunization anxiety related reaction
• coincidental event (non vaccine causes)

Question 22

t/f combining antigens increases the risk of adverse reactions

Answer 22

false, does not increase

Question 23

advantages of combination vaccines

Answer 23

• reduces cost of stocking and administering vaccines
• reduces cost of hc visit
• improving timelines
• addition of new vaccines into immunization programs

Question 24

t/f routine childhood vaccination (except bcg) are not contraindicated in children with asymptomatic hiv infection

Answer 24

true

Question 25

t/f symptomatic hiv/aids patients can take live attenuated vaccines

Answer 25

false

Question 26

focus of covid vaccine candidates

Answer 26

spike protein and its variants

Question 27

principles of mrna vaccines

Answer 27

- use nucleoside modified mrna - ex: pfizer, biontech, moderna - can be developed in labs using readily available materials

Question 28

principles of adenovirus vector vaccines

Answer 28

- non-replicating viral vectors - produce the antigen that elicits systemic immune response - ex: astrazeneca, sputnik v, convidicea, j&j

Question 29

safety monitoring for covid vaccine

Answer 29

- vaccine adverse event reporting system and v safe

Question 30

common side effects of covid vaccine

Answer 30

- pain at injection site!! - fatigue and headache - fever - resolve in a few days, responsive in paracetamol and nsaids, more common in younger - second shot has more side effects

Question 31

delayed reaction to covid vaccine

Answer 31

- occur within 5-14 d: warmth, pruritus over/near injection site, regional adenopathy (axillary) - not a contraindication - responsive to oral antihistamines and topical steroids

Question 32

t/f anaphylaxis vs covid vaccine is common

Answer 32

false

Question 33

t/f no evidence of causal relationship between covid vaccination and death

Answer 33

true

Question 34

absolute contraindications to covid vaccine

Answer 34

- hypersensitivity to vaccine components | - severe allergic rxn (anaphylaxis) after previous mrna covid vaccine (other therapy not a contraindication)