Media Release

18 August 2006

Meningococcal B immunisation rates high but fight not over

The fight against the epidemic strain of meningococcal B is far from over, despite new figures showing high immunisation completion rates.

More than one million young New Zealanders have had their first dose of the MeNZB™ vaccine, latest National Immunisation Register figures to July 2, 2006 show.

Of the children and teenagers who started their vaccinations against the disease, more than 90 per cent have now completed the course.

Among all young New Zealanders under 20 years old, about 80 per cent or about 949,000 have now completed three doses of the MeNZB™ vaccine. For Māori, the figure is about 72 per cent or about 201,000.

One of the reasons for lower immunisation rates among Māori in the register data is the different ways ethnicity is recorded in the 2001 Census and primary care practice records. This can lead to distortions in coverage estimates. The coverage for Māori children under 5 years of age could be underestimated by around 10 per cent.

The staggered roll-out of the programme means immunisation rates vary across District Health Boards.

Meningococcal B Immunisation Programme Director Dr Jane O'Hallahan says the high coverage rates are encouraging but it is crucial that under 20-year-olds who are not yet fully immunised complete their MeNZB™ vaccinations.

“Meningococcal B has already had a devastating effect on society, and while the immunisation programme has done much to reduce the number of cases nationally, the disease is still present."

So far this year there have been three deaths of under 20-year-olds from meningococcal disease. Two were epidemic strain, one in a partially immunised child and the other a fully immunised child. In the third case, the strain has not been able to be identified.

“Our focus must remain on breaking the natural cycle of this disease epidemic through the immunisation programme, and saving lives where we can. Results from an independent effectiveness study show the vaccine works. Those who are not fully immunised have a five times greater risk of getting the disease. While it is not a guarantee for everyone, the vaccine remains our most effective weapon in the war against meningococcal B."

“We know that the highest rates of meningococcal disease are in those under five and the younger the child, the higher risk of the disease. It is important that children and young people complete all three doses,” Dr O'Hallahan says.

For young babies who began their vaccinations before they were six months old, it is critical that they have all four doses.

Under-20s have until the end of the year to complete all three doses, while newborns and under-fives will continue to be offered the programme until 2009.

No vaccine provides 100 per cent protection. Most people who are immunised with MeNZB™ vaccine are protected against the epidemic strain, but the vaccine may not protect every person who receives the full course. The MeNZB™ vaccine will not protect against other strains of meningococcal disease and there is also up to a 28-day delay after the full course is completed for immunity to develop.

Parents need to be vigilant about the signs and symptoms of meningococcal disease. In the early stages the disease may look like influenza. It can progress very quickly and is difficult to diagnose. A baby or child might have a fever, be crying or unsettled, refuse drinks or feeds, vomit, be sleepy, floppy or hard to wake, dislike bright lights or have a rash or spots. An adult may have a fever or headache, a stiff neck, joint pain and aching muscles, vomit, be sleepy, confused, delirious or unconscious, dislike bright lights, have a rash or spots.

If you are concerned that you or someone in your household has meningococcal disease, ring a doctor or medical centre urgently.

ENDS


For more information about immunisation rates nationally and by District Health Board, download MeNZBTM Coverage Summary - National (PDF, 69 KB)


Questions and Answers

What is meningococcal disease?
Meningococcal disease is a bacterial infection. It causes severe illnesses including meningitis (an infection of membranes that cover the brain) and septicaemia (a serious infection in the blood). There are several strains of bacteria which cause meningococcal disease including A, B and C. MeNZB™ vaccine was developed to protect against the strain of meningococcal B causing the New Zealand epidemic.

Why are Māori coverage rates lower than other groups?
Statistics NZ population projections are based on prioritised ethnicity data from the 2001 Census. However, ethnicity may not have been recorded in the same way in the primary care practice records as it was in the census. This can lead to distortions in coverage estimates that particularly affect Māori. Prioritisation is the process whereby a single ethnicity is assigned where multiple ethnicities have been recorded. Māori ethnicity is first in the priority order. If Māori has been recorded on the census form as one of the ethnic groups a child belongs to, they will be counted as Māori in the estimated population. If, for example, a child is recorded as Pacific and Māori in the census, but only as Pacific in the practice record of the immunisation event, they will be included in the estimated population as Māori but in the coverage figures as Pacific. The immunisation coverage for Māori children under 5 years of age could be underestimated by around 10 per cent.

Does the MeNZB™vaccine work?
Yes. Preliminary results from the study confirm that the vaccine is 80 per cent effective. The study also shows that children and young New Zealanders who are not immunised against the epidemic strain of group B meningococcal disease have a five times higher risk of getting it than those who are fully-immunised.

How many meningococcal disease deaths have there been this year?
We have had six deaths from meningococcal disease so far this year. Three could not have been prevented by the vaccine programme as they were outside the age range for vaccine and of the three, only one was epidemic strain. There were three deaths in under 20-year-olds, the age group eligible for vaccination. For one the strain cannot be confirmed. One was epidemic strain but in a child so young they were only partially vaccinated. The third death was also epidemic strain but fully vaccinated.

How many epidemic strain Meningococcal B confirmed cases have occurred in under 20-year-olds?
In the five years before the introduction of the vaccine there was an average of 213 cases and seven deaths per year in under 20 year olds from the epidemic strain. In 2005 there were 82 epidemic strain cases and one death in this age group. In 2006, to date there have been 28 cases and two deaths.

How many vaccine breakthroughs have there been since the programme started?
A vaccine breakthrough is an individual who has become sick from the epidemic strain up to 28 days or more after the third dose. It is believed that it takes up to 28 days after the third dose for the vaccine to confer immunity. There have been 24 vaccine breakthroughs since the programme started in July 2004. Of these 24 vaccine breakthroughs, two were in infants who were overdue for their fourth dose.

When is the MeNZB™ vaccine given?
It is recommended that babies begin their MeNZB™ vaccinations at six weeks of age, followed by a second dose at 13 weeks or three months, a third dose at 21 weeks or five months and a fourth dose at 43 weeks or 10 months. For all other ages, three doses should be given at six-weekly intervals.

Is the MeNZB™vaccine safe?
Yes. There are no live meningococcal bacteria in MeNZB™ vaccine and it is not possible to catch the disease, or to become a carrier of the disease, from the vaccine. The vaccine has been manufactured to international standards. Extensive safety data collected during the programme was reviewed by an Independent Safety Monitoring Board (ISMB). The ISMB has stated that based on the data it has seen, it has no concerns regarding the safety of the MeNZB™ vaccine. Serious side effects are very rare however some people experience a mild temporary reaction such as redness at the site of the injection, a headache, nausea, a slight fever, feeling unwell, drowsy or irritable.

For interviews with Dr O'Hallahan please contact Michelle Quirke, Media Advisor, Ministry of Health, (04) 496 2265 or 027 434 6878.