Immunisation for MEN B

Question 1

There are how many serogroups for Neisseria Meningitidis?

Which cause invasive meningococcal disease (IMD) in humans?

Answer 1

There are 12 (determined by polysaccharide capsule of the bacterium)
A, B, C, Y and W

Question 2

What are the options for vaccinations?

Answer 2

Men C
Quadrivalent conjugate vaccine: A C Y W
NEW: Men B - four component vaccine (4CMenB)

Question 3

What is the epidemiology of IMD regarding serotypes?

Answer 3

Men B causes disease in infants (70% occurring in kids

Question 4

What do they mean that the MenB vaccine is a four-component vaccine? How is it different from the other vaccines?

Answer 4

Different: it is created from sub capsular proteins expressed on the surface of many strains of meningococcus that could elicit an immune response. Other vaccines were developed from polysaccharide capsule.
4 component: made up of four sub capsular proteins - neisseria heparin-binding antigen, H-binding protein, neiserial adhesion A and PorA

NB they initially tested the vaccine broken up into these four components but put them together because there is variability in the strains of MenB with regards to whether they have each component and what each component looks like.

Question 5

What percentage of the strains of MenB Have the four components of the MenB vaccine?

Answer 5

Around 66%

Meningococcal Antigen Typing System. This testing was done in the lab and had no clinical correlation

Question 6

Because the components are not the polysaccharide capsule, are they present in C, A, W and Y

Answer 6

All four components may be present in other groups, therefore it is possible that effectiveness of this vaccine could extend beyond MenB

Question 7

What are the difficulties creating a schedule for MenB

Answer 7

1. Because the bulk of the disease is in children

Question 8

What are the clinically significant adverse events?

Answer 8

Fever - 65% of infants had a significant fever 6 hrs post vaccine (32% with other vaccinations).
It also persisted > 24hs in 2/3

Question 9

What is the mortality rate of MenB IMD?

Answer 9

4.5%

Question 10

What is the estimated NNT?

Answer 10

38000-141000

depending on if you calculate the data including the risk for kids

Question 11

Who is high risk of IMD?

Answer 11

Asplenia or hyposplenia
Congenital complement, properdin, factor D or antibody deficiency
Kids on terminal complement inhibitor eculizumab
previous episodes of IMD
Laboratory work

Unclear: HIV and military

Question 12

Who should be vaccinated?

Answer 12

Those who are high risk.

but we are still awaiting recommendation from the National Advisory Committee on Immunisations