NZ needs a prick of conscience over national health disgrace

OPINION: Parliament's health select committee is about to begin an inquiry into children's immunisation rates. Committee chairman and National MP Paul Hutchison, a doctor, explains why.

New Zealand's failure to achieve anywhere near a 95 per cent completion rate for children's immunisations is a national disgrace that must be remedied. This inquiry specifically does not seek to make immunisation compulsory. There must be room for those who object (about 5 per cent).

For years New Zealand's completion rates have been far lower than in many other developed and undeveloped countries (which have completion rates up to 95 per cent), and there are significant inequities for many of our most vulnerable children (Maori uptake in Auckland and Counties Manukau is 64 per cent).

Completion rates of immunisation for children over four years of age is not known. That is shocking. For those under two years, the completion rate is about 76 per cent.

Pacific countries where I have personally worked are reported to have far better rates than New Zealand.

This poor record, despite our advantages, is partly a result of a poor focus on public health over a long period of time and partly a result of parental apathy and misunderstanding. Many New Zealand children unnecessarily suffer preventable diseases such as measles, whooping cough, pneumococcal pneumonia and other relatively common infectious diseases, despite immunisation being available at no charge. The mortality and related co-morbidity is high and could be prevented.

There is clear scientific evidence that the benefits of high levels of immunisation to the individual and to society far outweigh the disadvantages (very rare, but sometimes severe, side-effects).

Vaccines work by stimulating the immune system to develop antibodies to combat infections without the recipient suffering from the disease itself. The aim of vaccination is to offer protection to the recipient, who therefore becomes less likely to affect others, reducing the risk to those who have not been vaccinated.

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The concept of population or herd immunity means that, if there is a high level of immunity because a large enough number of a given population have been immunised, the remaining unimmunised members of the population will receive some protection from infection.

The level of uptake required for herd immunity varies for different diseases, and depends on how contagious the disease is and on the conditions that allow it to spread.

It is possible to calculate the proportion of people who should be vaccinated to prevent the disease from spreading.

For example, the World Health Organisation calculates that the herd immunity for measles is 92 per cent to 95 per cent; rubella 83 to 90 per cent; and polio 80 to 86 per cent.

In this way, people who cannot be immunised because they are immuno- compromised, for example because of cancer treatment, organ transplant or because of a weak immune system, also receive some benefit.

Where there are high levels of population immunity from high coverage, diseases such as measles can be eliminated, so long as vaccination coverage is maintained. In 1980, because of vaccination, smallpox was declared eradicated. In a similar way the World Heath Organisation is aiming to eradicate poliomyelitis - a condition that affected many New Zealand children in the past 60 years.

The OECD has noted that "simply because a service is offered, be it targeted or universal, does not mean that eligible families whose children would obtain benefits from it will take it up. The onus is on the parent to take up a service for their child."

Parents need clear evidence-based information for wise decision-making. Thankfully this is available for common childhood immunisations. New Zealanders have no excuses!

When I was a house surgeon at Wellington Hospital, a public health notice from the 1880s hung in the room of Professor Jeffrey Weston. The notice advised that any New Zealand parent who failed to immunise their child against smallpox would be fined [PndStlg]5 - a significant sum. Coercion or mandatory immunisation is not an option in modern-day society.

Nikki Turner of the Immunisation Advisory Centre and many others have worked tirelessly for years to improve New Zealand statistics, but they need support.

Strategies that improve immunisation coverage include better systems and assistance to health professionals, patient reminders and recalls, requiring children to present vaccination certificates before attending school, financial incentives, enhanced access to vaccination services, and community education measures to restore confidence in the science.

Improving the record in New Zealand will become harder the closer we get to the target. But, given the benefits, childhood immunisation completion rates (though improving) are appalling, and an unwavering effort is needed to achieve the established target of 95 per cent completion.

Closing date for submissions to the health committee's inquiry is February 12.