| Issue: | 28,2004/05 | Page: | 16-17 |
|
Abstract |
meningitis-examining the facts |
| Keywords: | Children, disease, vaccinations |
Every
winter the papers are full of the epidemic of
meningococcal disease. A person feels a bit fluey, possibly with
headache, for
a few hours only. If they don’t receive antibiotics they may be dead by
the
next day. It’s a tragic waste of a young life. The press ride the wave
of
hysteria gleefully. It is a worrying season for all parents.
Now a
new vaccine is being given to young people who are
most at risk. There is anxiety about this as well. Will it be harmful?
Do we
need it? Doubts and fears abound. Doubt is a sign of intelligence but
fear
prevents clear thinking. We need to know that the new vaccine will
work, save
lives, and that it is not harmful.
What
about our own natural immunity? When a bug, say a
flu virus, enters your body for the first time your immune system makes
two
things:
-
Antibodies that kill the virus
- Cells
in the blood, lymphocytes, which have a ‘memory’
of the bug.
This is
the ‘primary’ immune response. You feel ill but
your body is working hard to protect you.
If you
meet that germ again, your immune system is
primed. It ‘remembers’, and floods your system with antibodies aimed at
that
particular virus. You don’t feel ill because the virus is destroyed
quickly.
This is the ‘secondary’ immune response.
Immunisation
mimics the immune system. Part of a germ,
or an inactivated virus that can’t cause illness, is given. This
stimulates the
immune system to produce antibodies and ‘memory’ lymphocytes. Later, if
the
real germ is taken on board, the body mounts a rapid secondary response
and
fights it off without the illness occurring. If enough people are
immune to a
bug, it rarely causes illness in the community, even in the
un-immunised, as
there is not enough of it around. This is called ‘herd immunity’.
Our
immune system, like that of animals, is a neat
adaptation but it is not perfect. People become ill, and sometimes die
of
infections. This is natural. However, it causes much human suffering.
Some
might say we have to accept this; others feel we have a duty to reduce
suffering if we can.
New
Zealand has the highest rate of meningococcal
disease in the developed world. Between 1991 and the end of 2003, it
affected
5293 people. Many have been left permanently maimed or deaf. Two
hundred and
sixteen died. On average, that’s 14 or 15 deaths each year. Eighty per
cent of
these were people under 20 years of age. Children under 1 year are most
at
risk.
Some New
Zealanders are more likely to be affected. A
Pacific Island child has a 1 in 66 chance of catching it by the age of
5 years.
A Maori child has a 1 in 117 chance, and for ‘European’ children,
1chance in
438. However, there are more Pakeha children so they make up a third of
those
affected.
There
are different types, or strains, of meningococcal
bacteria. In New Zealand a particular strain of Group B meningococcus
is
responsible for over 70% of cases. It is this strain that the new
vaccine is
aimed at.
Why is
this bug, the meningococcus, so dangerous?
- Well,
firstly, 20% of us have it living quietly in our
nose and throats. So it is always around. Occasionally it invades the
blood
stream or lining of the brain (the meninges), causing septicaemia or
meningitis
respectively.
-
Secondly, it has a special coat, or capsule, which the
body’s immune system cannot recognise. This means the bug can overwhelm
us
before we can produce antibodies against it.
The
vaccine, MeNZB, is tailor-made for the New Zealand
strain. It is expected to cut the number of cases by over 70%. This
will occur
if 90% of those between 6 months and 20 years of age receive the
vaccine as
planned. Immunisation has started in South Auckland already, and will
progress
around the country over the next 18 months.
OK, but
will it work? In the recent New Zealand clinical
trial, children were given 3 doses, 6 weeks apart. Seventy-five percent
of them
produced high levels of their own protective antibodies. Even with
lower
levels, most of the others should be protected from the disease.
In Cuba
there was a similar epidemic. Meningococcal
disease affected 14 people out of every 100,000/ year before
immunisation
started. Now less than 1 person per 100,000 catches it. The vaccine has
been
part of their childhood immunisations for nearly twenty years.
But is
it safe? Good question. When deciding to give a
vaccine to otherwise healthy people, this is the most important
consideration. Similar vaccines have
been used in Chile, Brazil, Cuba and Norway. In trials in Norway
180,000 people
had no serious adverse reactions due to the vaccine. In a trial in
Chile only
one person had a serious allergic reaction out of 40,000. Around 60
million
doses have been given in Latin America.
The main
problem is that the injection causes pain. The
local reaction to the vaccine is usually mild, meaning a child cries if
the
injection site is touched. In 10-20%, however, the child may have pain
when the
injected leg is moved. This improves after 2 days.
Not
surprisingly, 40% of small children seem irritable
afterwards. Ten per cent have a fever over 38 degrees. It will not
prevent
disease caused by the less common strains of meningococcus. It cannot
eradicate
the germ from those simply carrying it in their throats. So ‘herd
immunity’
will probably not occur. Un-immunised people will still be at risk.
Some
people fear the antibodies produced by vaccines may
harm us. Surely it’s not right to put foreign material into ourselves.
- Germs invade
our bodies continually in childhood, that’s how we develop immunity.
Unfortunately, the meningococcus doesn’t play by the rules.
- Billions of doses
of vaccines have been given
worldwide, including during the eradication of smallpox. There’s no
evidence
that immunisation produces antibodies that attack our own bodies (so
called
‘auto-immune’ diseases were around long before vaccination).
- We
intentionally put foreign stuff in our bodies all the time (ever been
to
McDonalds?).
What if
Helen Clark is in cahoots with the drug company
making the vaccine? Scepticism is a healthy response where there is
doubt,
especially where government and multi-national companies are involved.
Unfortunately most conspiracy theories rely on suspicion and fear
rather than
information.
If you
believe the government is knowingly spending tax
dollars on a scheme that will harm our children, only to profit a few,
I
suggest armed revolution as the appropriate response.
We make
decisions based on our knowledge and experience,
our world view and our politics. There are two decisions to make here.
One is
for our children and ourselves. The other is whether we act as a
community to
protect all its members.
The
vaccine is safe and effective, but it hurts.