pre-IC11

Question 1

Characteristics of and distinctions among live attenuated vaccines and inactivated vaccines (including polysaccharide vaccines, toxoid vaccines and recombinant vaccines)

Answer 1

Live attenuated vaccines confer life-long immunity while inactivated vaccines often require boosters/ several doses.

Live vaccines need to be refrigerated while inactivated vaccines could be easily stored and transported.

Question 2

Live attenuated vaccines - what and examples

Answer 2

Weakened viruses; measles, mumps, rubella, varicella; rotavirus

Question 3

Whole, killed inactivated vaccines - what and examples

Answer 3

Dead virus; Hep A, polio, rabies

Question 4

Polysaccharide (subunit) vaccines - what and examples

Answer 4

Parts of the pathogen e.g. proteins; Hep B, pertussis, pneumococcus, influenza

Question 5

Toxoid inactivated vaccines - what and examples

Answer 5

Toxins produced by pathogen is inactivated; Diphtheria, tetanus

Question 6

Recombinant inactivated vaccines - what and examples

Answer 6

May contain no actual virus (e.g. Hep B, HPV) or modified strain of virus (e.g. live oral typhoid)

Question 7

Precautions for use of live attenuated vaccines

Answer 7

• Avoid in pregnant women
• Usually not given in infancy (<1 year old)
• Avoid in severely immunocompromised patients (Hematologic or solid organ malignancies, Immunosuppressive meds, chemotherapy, HIV with CD4 < 200)
• 2 live vaccines (IM/ SC route) either given on the same day or spaced 28 days apart
• Spaced 3‐10 months apart from administration of antibody containing
  products eg immunoglobulins, blood transfusion

Question 8

Herd immunity

Answer 8

Enough of the population is immunised to contain the spread of the disease, and most community members are protected, including the unimmunised individuals.

The percentage of population that needs to be vaccinated for herd immunity depends on how contagious the disease is.

Question 9

Vaccines included in National Childhood Immunization Schedule (till 17 y/o)

Answer 9

• Bacillus Calmette-Guerin (BCG)
• Hep B
• Measles, mumps, rubella
• Diphtheria, tetanus, pertussis (DTap for D1-D3 and B1 and Tdap for B2)
• Inactivated poliovirus
• Haemophilus influenza Type B
• Pneumococcal conjugate (PCV10/ PCV13)
• Varicella
• HPV
• Influenza

Question 10

Vaccines included in National Adult Immunization Schedule

Answer 10

• Influenza
• Pneumococcal conjugate (PCV13)
• Pneumococcal polysaccharide (PPSV23)
• Tdap
• HPV
• Hep B
• MMR
• Varicella

Question 11

General considerations in vaccine use

Answer 11

Effectiveness & factors that could affect effectiveness:
* Site vaccine given (hepatitis A/B vaccine as IM in deltoid, not gluteus)
* Patient age & immune status (influenza vaccine less effective in 80 vs 60 yo)
* Cold chain problems (not kept at recommended temperatures)

Adverse effects:
* Mild & common: Pain, redness and swelling at injection site, headache, myalgia
* Uncommon: Fever, hematoma
* Severe but rare: Anaphylaxis, hypersensitivity

Question 12

Does primary dose mean only a single dose of vaccine?

Answer 12

No. Primary dose can be a single dose or a few doses (primary priming series)

Question 13

Contraindications and precautions for vaccines

Answer 13

Reasons why this patient should not get this vaccine (at this time)
* Allergy to vaccine or components
* Moderate/severe illness (fever > 38 degC)
* Bleeding risk (on anti‐coagulation or low platelet counts) ‐ precaution
* Pregnancy (live vaccines)
* Immunocompromise (live vaccines)

Question 14

Which vaccines cannot be Simultaneously administered?

Answer 14

Pneumococcal conjugate vaccine (PCV) and meningococcal conjugate vaccine in patients with functional or anatomical asplenia (no spleen).

In these patients, there should be a 4‐week interval btw the administration of the two vaccines to avoid interference of the meningococcal conjugate vaccine with PCV.