It is becoming more apparent that opposition from anti-MeNZB groups is growing here in New Zealand, particularly as it gains support from parents worried their children are being adversely affected by the vaccine. It is true that the side effects of the vaccine are fairly common, particularly pain, swelling, irritability and possibly a fever. Such side effects, however minor and ultimately trivial in the face of full blown meningitis are giving anti-vaccine campaigners ammunition. Needless to say, many of these effects are being completely over done and probably over dramaticised. I couldn't help but note the parents who appeared on TV1 on Close Up, who demanded that they have assurance of no side effects at all if they had their child get the other two booster shots.
Now, however distressing such side effects can be, especially when you watch these sort of things happen to your own children there are a few things to note. Firstly, the immune system is ultimately a biological weapon. It's an extremely potent and very well armed weapon that has been selected for over evolution for one task: To destroy invaders. To do so it uses numerous chemical, hormonal and cellular mediators to eradicate the invader and unfortunately like any human made weaponry sometimes there is a little collateral damage. Most of the 'side effects' that people think are horrible and the anti-MeNZB campaigners are so shrill about is the vaccine actually doing something. Such vigourous reactions, although thankfully not so vigourous as to be life threatening in any sense except for rare cases, is in fact demonstrating the vaccine is being recognised and the immune system is doing something about it.
Secondly, it's important to realise that this vaccine has been made with considerable difficulties that other vaccines (with less side effects, but often similar ones) do not end up with. The first problem is that the organism that commonly causes meningitis here in NZ, Neisseria meningitidis surface capsule is made of a substance similar to ones found on our cells. This induces considerable autoimmunity problems when it is used as a vaccine, plus it isn't very immunogenic anyway. Neisseria meningitidis group A and C have a different kind of surface and the vaccines produced from them have considerably less side effects.
As a result, we've based our vaccine on a similar one made in Norway to a similar group B strain of N. meningitidis. The way they (and ourselves) produced this vaccine was by spinning the bacteria to seperate out structures on the bacterias surface called outer membrane vesicles. These structures are known to be immunogenic (illicit protection) while they do not induce autoimmunity (they are novel to the bacteria). These vesicles also come with another bit of the bacteriums outer surface, lipopolysaccharide or LPS. LPS is something that the immune system really reacts vigourously towards and is probably why side effects such as irritability are so common with this vaccine.
In saying that however, LPS also helps what isn't the best antigen that we would like to do a lot better, although the studies in Norway confirmed that three booster shots are required to establish long term memory. Unfortunately, the very side effects which are lambasted by the anti-vaccinists are also the very proof that the vaccine is properly working and doing its job correctly. The difficulty, going back to my point about the family demanding assurance on close up, is in explaining that side effects are not always a bad thing. When you're essentially priming a weapon so that it is ready to meet an invader, it should be expected that in the build up of suitable arms and defences that you would get some indication of this process is going on.
