Heather Roy's Diary: Meningitis Vaccine
Heather Roy's Diary
At the time of the roll out of the Meningococcal vaccine there was much publicity around the issue. Parents received consent forms for their children outlining the advantages of having their children vaccinated and possible adverse events were outlined. If a parent or guardian did not sign the form their child was not vaccinated. The Minister of Health, in response to a question by National Health spokesman Tony Ryall in Parliament last week, said that no unexpected adverse events had been experienced. The issue is a sensitive one and emotion often gets in the way of scientific evidence. ACT considers the best situation to be one where parents are well informed of the benefits and problems, and are therefore able to make an informed choice.
There are many issues that have not been well publicised in this whole debate, and some of them are discussed below.
New Zealand has recently been in the unusual position of having to develop its own vaccine. We can usually buy "off the shelf" preparations from larger countries, an arrangement that works to our advantage, as development costs for new medical treatments are very high. But when it comes to meningococcal B we seem to be on our own.
For reasons that aren't understood, New Zealand has a rate of meningococcal infection that is ten times that of comparable countries, and the only other Western country that has been in this situation is Norway. There is much we can learn from studying the Norwegian epidemic. From their experience it seems possible that our own epidemic could still have a long way to run. Norwegian advances in developing a vaccine, however, are of only some use to us - since they suffered from a different strain.
Despite New Zealand's high rate of meningococcal infection the news is not all bad - we have a low death rate. However sufferers are often left with nasty side effects, such as loss of hearing in one ear, brain damage and cerebral palsy, amongst others. In fact New Zealand has the best survival rates for Meningococcal meningitis in the world. A high level of awareness by parents and doctors means that effective treatment tends to be started early. And now we have a vaccine, MenzB.
The vaccine is not perfect, as it does not produce complete immunity in all cases, and even then several boosters are required. But with that caveat it usually works and that gives it the potential to stop our current meningitis epidemic in its tracks. The vaccine has had no shortage of critics and some have been more reasonable than others. The online news organization "Scoop" suggests that we are simply getting recycled Norwegian vaccine that has not been through the full testing process in New Zealand.
Normally a new medical treatment has to go through three phases of human trials following extensive animal testing.
Phase One: Given to healthy volunteers. The human guinea pigs are almost always young men as they must be healthy and the developers don't want to take any risk of inadvertently treating a pregnant woman.
Phase Two: An "Open" trial using the target population, which in the case of meningitis is anyone under twenty. Both patient and doctor know they are getting the real treatment. In this case vaccines against different strains were tried with the target population.
Phase Three: Large scale "Blind" trial in which the treatment is compared to an inactive but identical agent. Comparisons can be drawn as to the effectiveness of the agent.
No phase three trials have been done in New Zealand on the MenzB vaccine, although the first injections after the Phase 2 trial were administered under tightly controlled conditions. The line of argument against the vaccine is essentially that it has not been proven effective in the New Zealand situation and could turn out to be a waste of money. Given that more than 1,000,000 people have been vaccinated with three million doses we shall soon know.
The second line of argument is that the vaccine is dangerous and parents shouldn't allow their children to have it. Here things have become a little silly. In the last week of parliament, National Party Health Spokesman Tony Ryall asked Health Minister Pete Hodgson if the vaccine was safe when 33 cases had been successful in ACC claims for injury as a result of the vaccine being administered. Mr Ryall was being, at best, mischievous in trying to insinuate that the vaccine was faulty in some way.
Tony Ryall ignored scientific knowledge and conveniently confused cause and effect. What he didn't say was that most of the ACC claims in question could be simply the result of having an injection. Several of the successful ACC claims were of a minor nature. To make a claim of causation is at best mischievous, and at worst, dishonest. ACC is a no- fault system - the fact that claims have been successful means only that an injury has occurred, not that the vaccine is to blame. Despite knowing this Mr Ryall irresponsibly used ACC data to suggest that the vaccine is somehow the cause of the injuries compensated for. The danger is of undermining a campaign to fight a deadly disease with parents who have to make a decision.
Any debate about meningitis vaccinations should be based on safeguarding