Invasive Meningococcal Vaccination

Question 1

Which serogroup have the highest incidence?

Answer 1

Serogroup B - 70% cases in <5yo, ~50% of all age cases

Serogroup C - peaks in adolescence, 12-19%, highest fatality rates

Y - 17%

W - 5%

Other/unknown - 4-9%

Question 2

How does N. meningitidis present

Answer 2

Most common: septic shock, meningitis

Others: sepsis, pneumonia, septic arthritis, pericarditis, occult bacteremia

Question 3

What is the outcome of meningococcus infection

Answer 3

~20% sequelae at discharge

5% mortality rate

Question 4

What vaccines are currently available?

Answer 4

Men-C-C: all infants at 12mo

Men-C-ACYW: adolescents, high risk groups (2x doses)

4CMenB - high risk groups

Question 5

Why type of vaccine is Men-C-ACYW, and what are the age recommendations

Answer 5

Conjugated

• Men-C-ACYM-DT = to diphtheria toxoid protein (>9mo)
• Men-C-ACYM-CRM = to CRM197 protein (2mo-2y)
• Men-C-ACYM-TT= to tetanus toxoid protein (>9mo)

Question 6

What type of vaccine is 4CMenB - and what are its challenges

Answer 6

Vaccine targets nonploysaccharide surface antigens

Requires 3 doses in infants, and titres may wane over 12mo

Question 7

What medical conditions increase the risk for IMD (7)

Answer 7

1. Asplenia - functional or anatomic
2. Properdin deficiency
3. Factor D deficiency
4. Complement deficiency
5. Eculizumab use —> acquired complement deficiency
6. Primary antibody deficiency
7. HIV

Question 8

What exposures increase risk for IMD (4)

Answer 8

1. Lab workers who work with meningococcus
2. Military personnel living in close quarters
3. Travellers to endemic areas (Sub-Saharan Africa, Hajj pilgrims)
4. Close contacts of IMD

Question 9

What is the vaccine schedule recommended for high risk individuals

Answer 9

• Immunisation with Men-C-ACYW-CRM and 4CMenB at time of diagnosis
• 2 to 3 doses of Men-C-ACYW (even if they got Men-C-C) q8wk
• 2 to 3 doses of 4CMenB q8wk (q4wk if >11y)
• Booster of both at 12-23mo then q3-5y until 7 years old, then q5y

Question 10

How should travellers to endemic areas be immunised

Answer 10

1. Men-C-ACYM:
   - 2-3 doses if <1y
   - 2 doses if 12-23mo
   - 1 dose if >24mo
2. 4CMenB if travelling somewhere with ongoing outbreak
3. No Men-C-C at 12mo IF already have 1 dose of Men-C-ACYM and getting second dose within 8 weeks

Question 11

How should close contacts of IMD be managed?

Answer 11

If eligible for chemoprophylaxis AND strain is vaccine-preventable = give vaccine even if has been vaccinated prior