Vaccines

Question 1

What is active immunization?

Answer 1

Stimulating immune system response to create immunologic memory

Question 2

What is passive immunization?

Answer 2

After exposure to infection, infusing antibodies or immunoglobulins for immediate protection (no time to vaccinate)

Question 3

Describe live attenuated vaccines and their characteristics (i.e. measles, mumps, rubella, varicella, rotavirus)

Answer 3

Virus weakened via passage in medium where it replicates poorly
+ Activates killer T cells
+ Can provide lifelong immunity with 1 or 2 doses
- Refrigeration needed
- Less safe for immunocompromised pts

Question 4

Describe inactivated vaccines and their characteristics (i.e. polio, hepatitis A, rabies)

Answer 4

Pathogen treated with heat/chemicals to kill it
+ Easy storage and transport
+ Low risk of infection
- Weak immune response, may require boosters

Question 5

Describe subunit vaccines and their characteristics (i.e. influenza, hepatitis B, pertussis, pneumococcus)

Answer 5

Can be Protein/Polysaccharide/Conjugated
1 or more parts of pathogen isolated to invoke immune response
\+ Low risk of adverse reaction
\+ Suitable for immunocompromised pts
- Difficult to manufacture
- May require boosters

Question 6

Describe toxoid vaccines and their characteristics (i.e. diphtheria, tetanus)

Answer 6

Toxin produced by pathogen inactivated and used to invoke immune response
+ No risk of infection
+ Stable, easy to distribute
- May require boosters

Question 7

Describe recombinant vaccines and their characteristics (i.e. HPV, hepatitis B, live oral typhoid)

Answer 7

Vaccines made using Genetic engineering

May contain no actual virus i.e. HPV, Hepatitis B or modified strain of virus i.e. live oral typhoid

Question 8

Precautions of live vaccines?

Answer 8

Avoid in pregnant women 
Usually not for infants
Avoid in severely immunocompromised pts
Avoid another live vaccine in 28 days
Space 3-10mnths apart from antibody containing products (blood transfusion/immunoglobulins)

Question 9

Available vaccines for respiratory transmission?

Answer 9

Influenza, pneumococcus,
Meningococcus,
Diphtheria, pertussis
Hemophilus influenzae
Measles, mumps, rubella
Chickenpox
BCG (Tuberculosis)

Question 10

Available vaccines for Food/water transmission?

Answer 10

Hepatitis A, typhoid, cholera, Rotavirus

Question 11

Available vaccines for vector transmission?

Answer 11

Yellow fever, Japanese Encephalitis Dengue

In development: malaria

Question 12

Available vaccines for blood/fluids transmission?

Answer 12

Hepatitis B, Human papilloma virus

Question 13

Available vaccines for contact transmission?

Answer 13

Tetanus
Rabies
Shingles

Question 14

Explain herd immunity

Answer 14

Enough of the population is vaccinated to contain spread of disease, protecting unimmunized individuals

Question 15

What are the 11 vaccines in the National Childhood Immunization Schedule (NCIS) ?

Answer 15

Bacillus Calmette-Guerin (BCG)
Hepatitis B
Diphtheria, Tetanus, acelullular Pertussis DTaP (paediatric) --> Tdap (later date)
Inactivated poliovirus (IPV)
Haemophilus influenzae type b (Hib)
Pneumococcal conjugate (PCV10 or PCV13)
Pneumococcal polysaccharide* (PPSV23)
Measles, mumps and rubella (MMR)
Varicella (VAR)
HPV2 or 4
Influenza* (INF)

*Recommended for pts with specific medical condition/indication

Question 16

What are the 8 vaccines in the National Adult Immunization Schedule (NAIS) ?

Answer 16

Tetanus, reduced Diphtheria, acelullular Pertussis* (Tdap)
Influenza* (INF)
Pneumococcal conjugate* (PCV10 or PCV13)
Pneumococcal polysaccharide* (PPSV23)
Measles, mumps and rubella (MMR)
Varicella (VAR)
Hepatitis B
HPV2 or 4 (females)

*Recommended for pts with specific medical condition/indication

Question 17

What are the factors that affect vaccine effectiveness?

Answer 17

Variation by vaccine (Hep B 95% vs Varicella 90%)
Site of vaccination (Hep A/B IM in deltoid, not gluteus)
Patient age and immune status
Cold chain problems

Question 18

What are some adverse effect of vaccines?

Answer 18

• Mild & common: Pain at injection site, headache, myalgia
• Uncommon: Fever, hematoma
• Severe but rare: Anaphylaxis, hypersensitivity

Question 19

Contraindication and precautions for vaccine use?

Answer 19

• Allergy to vaccine or components
• Moderate/severe illness (fever > 38C)
• Bleeding risk (on anti‐coagulation or low platelet counts) ‐ precaution
• Pregnancy (live vaccines)
• Immunocompromised (live vaccines)

Question 20

Most vaccines can be administered simultaneously or within the same day. What are the exceptions?

Answer 20

Pneumococcal conjugate vaccine (PCV) and meningococcal conjugate vaccine in patients with functional or anatomical asplenia
- Space them out in a 4 week interval
Live vaccines should be given 28 days apart

Question 21

If a patient misses a vaccine dose, what should be done?

Answer 21

Give the dose asap

- Additional doses not required

Question 22

What is the role of adjuvants in vaccines?

Answer 22

Enhance the body’s immune system

- possibly by keeping antigens near site of injection (for easy access to immune cells)

Question 23

What is the role of antibiotics in vaccines?

Answer 23

Used to remove contaminants in manufacturing process, removed in final product (residues remain)

Question 24

What is the role of stabilizers in vaccines?

Answer 24

Ensure components remain stable and effective

- i.e. MgSO4, lactose, gelatin, sorbitol, msg

Question 25

What is the role of preservatives in vaccines?

Answer 25

Prevent contamination

- i.e. Thiomersal, phenol, phenoxyethanol

Question 26

What is the role of Trace components in vaccines?

Answer 26

Residues that persist in trace quantities despite removal in manufacturing process
- i.e. Formaldehyde (extremely low level that does not cause harm)

Question 27

What are the main components of a vaccine?

Answer 27

Adjuvants
Antibiotics
Stabilizers
Preservatives
Trace components
Active components