Vaccines

Question 1

What is the difference between Innate & Adaptive immunity?`

Answer 1

Innate Immunity:
- Basic resistance to disease (immunity)
- Provides immediate protection
- Same response regardless
- No memory
(Eg. Phy barriers (Skin/mucosa), Physiologic factors (Gastric acid), Process (Inflmm), Cells of immune system)

Adaptive Immunity:

• Protection develops more slowly (days)
• Developed after exposure to antigen
• Effective only against specific antigen
• Has memory (enhanced ability to deal with recurring antigen)
• -> Upon 1st exposure, developement of pri immune response with proliferation of activated B cells & T cells into effector cells, and some to memory B & T cells

Question 2

LO1: How do vaccines elicit an immune response & provide protection?

Answer 2

• Prime the adaptive immune system to provide a long-lasting targeted response that prevents infection
• By memory from the Adaptive Immunity (Basis of vaccination)
• -> Activation of memory cells –> Secondary response with shorter lag time between exposure & production of response + Heightened state of activity
• -> Faster & stronger immune response

Question 3

What does it mean by ‘Vaccination is a form of active immunization’

Answer 3

Provide immunization before host even comes into contact with the pathogen

Question 4

LO2: Characteristics & distinctions of LIVE VACCINES

Answer 4

What: Weakened virus, often by repeatedly passing through tissue culture in which it replicates poorly

• > Immunogenic: Activates killer T Cells
• 1/2 doses can provide lifelong immunity
• Temp-sensitive: Must be refrigerated
• < safe for people with weakened immune system
• Need to be given spaced apart from other live vaccines
• Not generally given to infants

Eg: Measles, mumps, rubella, varicella, rotavirus

Question 5

LO2: Characteristics & distinctions of INACTIVATED VACCINES (non-living)

Answer 5

What: Inactivated by treating with heat/chemicals to kill it

• Easy to store & transport
• Low risk of causing infection
• Elicits weaker immune response
• May require several doses/boosters to attain adequate response

Eg: Polio, Rabies, Hep A

Question 6

LO2: Characteristics & distinctions of SUBUNIT VACCINES (non-living)

Answer 6

What: One/more parts of the pathogen are isolated & used to evoke an immune response

• Low risk of causing adverse reaction
• Can be used in people with weakened immune systems
• Can be difficult to manufacture
• May require boosters to attain adequate response

Eg: Hep B, Influenza, Pertussis Pneumococcus

Question 7

LO2: Characteristics & distinctions of TOXOID VACCINES (non-living)

Answer 7

What: Toxin produced by pathogen is deactivated & used to produce the immune response

• Unable to cause disease/ spread
• Stable, easy to distribute
• May require boosters to maintain immunity

Eg: Diphtheria, tetanus

Question 8

LO2: Characteristics & distinctions of RECOMBINANT VACCINES (non-living)

Answer 8

What: Produced using genetic engineering. May contain no actual virus/ modified strain of virus (as with live oral typhoid)

Eg: Hep B, HPV

Question 9

Precautions with live vaccines

Answer 9

• Avoid in pregnancy/ severely immunocompromised
• -> Concern for uncontrolled replication -> Cause actual clinical infection
• Not usually given to infants
• Avoid giving another live vaccine within 28 days
• Space 3-10 mths apart from other ab-containing products

Question 10

LO3: List vaccines available for infections transmitted by RESPIRATORY route

Answer 10

• Influenza
• Pneumococcus
• Meningcoccus
• H. influenzae
• BCG (Tuberculosis)
• MMR (Measles,Mumps,Rubella), Chickenpox

Question 11

LO3: List vaccines available for infections transmitted by FOOD & WATER route

Answer 11

• Hep A
• Typhoid
• Cholera
• Rotavirus

Question 12

LO3: List vaccines available for infections transmitted by VECTOR-BORNE route

Answer 12

• Yellow fever

- Jap Encephalitis Dengue

Question 13

LO3: List vaccines available for infections transmitted by BLOOD & BODILY FLUIDS route

Answer 13

• Hep B

- HPV

Question 14

LO3: List vaccines available for infections transmitted by CONTACT route

Answer 14

• Tetanus
• Rabies
• Shingles

Question 15

LO4: Describe principles of Herd Immunity

Answer 15

High vaccination rate in population such that most community members are protected, even the unimmunized individuals

Question 16

What is the diff between Primary & Booster dose?

Answer 16

Pri: Single/Few doses
Booster: Additional dose of vaccine to maintain protective levels of antibody

Question 17

LO5: List vaccines in NCIS

Answer 17

• BCG
• Hep B
• DTap
• Tdap
• MMR
• VAR
• IPV
• Hib
• INF
• PCV10/PCV13
• HPV2/HPV4

Question 18

LO5: List vaccines in NAIS

Answer 18

• Hep B
• MMR
• VAR
• HPV (Females 18-26yo)
• Tdap (1x during each pregnancy)
• INF (1x anually/season for >65yo or if have indication)
• PCV13 & PPSV23 (1x for >65yo or if have indication)

Question 19

LO6: Discuss the general considerations for vaccine use

Effectiveness & Adverse Effects

Answer 19

• Effectiveness (Varies by vaccine)
• Site vaccine given (Eg. Hep A/B IM in deltoid, not gluteus)
• Patient age & immune status
• Cold chain problems

Adverse effects:
Common - Pain @ inj site, headache, myalgia
Uncommon - Fever, hematoma
Rare (Severe) - Anaphylaxis, Hypersensitivity

Question 20

LO6: Discuss the general considerations for vaccine use

Contraindications & Precautions

Answer 20

• Allergy
• Moderate/severe illness (Fever > 38C)
• Bleeding risk (Caution with administration)
• Pregnancy (Live vaccines)
• Immunocompromised (Live vaccines)

Question 21

LO6: Discuss the general considerations for vaccine use

Simultaneous administration & Missed Doses

Answer 21

• Mostly no problem
• EXCEPTION: PCV vaccine & meningcoccal conjugate vaccine shld be given 4 weeks apart for pts with functional/anatomical asplenia
• Missed dose: Dose given as soon as possible

Question 22

LO7: Other components in vaccine

Answer 22

1) Stabilisers (Sorbitol, Mg Sulfate)
- To ensure components stable & effective

2) Preservatives (Thiomersal)
- Prevent contamination

3) Adjuvants (Al hydroxide/phosphate)
- Enhance body’s immune response
- Thought to help keep antigens near site of injection (?)

4) Antibiotics (Gentamicin, Neomycin)
- Prevent bacterial contamination
- Later removed, only residual qty remain after production process

5) Trace components (Formaldehyde)
- Left-over from production