So, how do we prevent meningitis?
Well, if it's the meningococcs we’re trying to prevent
and we want to make sure that we
prevent this in all our young people,
we give them a quadrivalent conjugate vaccine.
And what this contains is
capsular polysaccharide antigens
from the most common types
of meningococcal meningitis.
The most common is actually group B.
You notice that's not listed here.
So, the other common types,
A, C, Y and W135,
those are the other most common types of meningococcus.
And this is recommended for all persons aged 11 to 18 years
and for high risk persons up to 55 years of age.
For example, patients who would
have trouble with the meningococcus,
like somebody with a complement disorder,
somebody with no spleen.
They are very susceptible to various kinds of
bacteria in the blood stream and meningitis.
To laboratory personnel who work
around cultures of the meningococcus
and to travelers in the African meningitis belt,
there is a band in Africa –
in equatorial Africa where meningitis caused
by the meningococcus is actually epidemic.
So, travelers to this area should receive this vaccine.
And they also should get a booster dose
at the age of 16 or five years after the prior dose.
And all high risk children
should get this quadrivalent vaccine.
So, what about persons who
have been exposed to an individual
who has this dreaded disease
of meningococcal meningitis.
They certainly – if they've not
been previously immunized,
they need to receive the meningococcal vaccine
and they would – that would
be close contacts of somebody.
And usually, we’re talking
about household contacts.
It’s controversial as to whether,
for example, a physician involved in
the resuscitation of a patient with this
should get meningococcal vaccine.
But, personally, I would recommend,
if they're involved
in mouth-to-mouth resuscitation
that they should get the vaccine.
In the United Kingdom,
the partner of someone with confirmed meningitis
who has kissed a close contact recently
needs to receive antibiotics.
all of those cases need to be reported
to the public health authorities in the UK.
Now, you notice,
we didn't talk about the most common form of meningococcal meningitis
and that is group B.
And the problem with group B is that the
capsule is essentially covered with sialic acid,
which is very much like the surface
of many mucosa in the human body.
we don't develop antibodies very well.
So, if you tried to immunize with group B
you don't get a good response.
So, what's been developed is this
vaccine specifically targeting group B meningococcal vaccine.
It’s called Trumenba
and it was licensed in 2014.
And it's the first vaccine that
protects against serogroup B disease.
And the vaccine is based not on a capsule
of the organism,
which has that sialic acid,
but on the outer membrane protein.
So, this would be indicated for immunization
to prevent serogroup B disease.
And I believe that all persons
10 to 25 years of age should get it,
especially since serogroup B is the most
common form of meningococcal meningitis.
We also want to prevent
And for that, we have 23 serotypes
that we are interested in.
And these are the most common serotypes
of that organism that cause disease in humans.
And we’ve got a vaccine that
contains those 23 antigens.
And the efficacy overall is fair to middlin’.
It’s up to 75% of individuals.
And we are trying to target
normally the elderly persons in a nursing home.
We especially want to target patients who have no spleen
because the spleen is an important organ
in our defense against encapsulated
organisms like the pneumococcus.
But remember, in patients with sickle cell anemia,
by the time they reach adulthood,
they have essentially auto infarcted their spleen
and have no functional spleen left.
So, they need to be immunized
against the pneumococcus particularly.
And because pneumococcal disease
is prevalent in elderly persons,
we also recommend this
vaccine for elderly persons.
And it's been shown to be cost-effective.
And unfortunately, the duration
of protection is relatively short.
So, we generally re-immunize patients with
the pneumococcal vaccine after about five years.
There's a new vaccine – relatively new –
called the pneumococcal conjugate vaccine, PCV 13,
which has 13 of the most common serotypes
and it's been conjugated to a
harmless variety of diphtheria toxin.
And the purpose for that is to induce
some T cell associated immune response.
And you get a more vigorous
antibody response with T helper cells.
And the pneumococcal conjugate
vaccine is given in four doses
and it does reduce the risk of invasive disease
even if given to kids and adults
because the disease often
is spread by kids to us adults.
And it’s currently licensed for use in
children and adults over the age of 50.
There's also a Haemophilus influenzae B vaccine
and that has resulted in almost
the disappearance of H. flu meningitis
in the United States and other developed countries.
But H. influenzae B is still an important cause
of meningitis in underdeveloped countries.
But we usually do not vaccinate kids
at less than six weeks of age
because they may get some
immune tolerance to the antigen.
So, the minimum age that we
begin vaccinating these patients
is six weeks of age
and the minimum interval is
four weeks for the primary series.
And that concludes my
discussion of bacterial meningitis.
I hope you found it useful.