Extra protection for babies with 4th MeNZB dose
12 January 2006
Extra protection for babies with 4th MeNZB dose
A 4th dose of the MeNZB vaccine is being introduced for all babies who received their 1st dose before they were six months old.
This follows medicines regulator Medsafe granting approval for a 4th dose of the vaccine to be administered to babies, the age group at greatest risk from the country's group B meningococcal epidemic.
A 4th dose was signalled as likely when the vaccine was first licensed for young babies.
The Ministry of Health says the 4th dose, to be introduced in immediately, will significantly boost the immune response of babies and offer them increased protection from the disease. The 4th dose will be given to babies when they are at least 10 months old, and a minimum of four months after their 3rd dose, or as soon as possible after that time.
The Ministry's Meningococcal B Immunisation Programme director Dr Jane O'Hallahan says it is vital this vulnerable group receive the 4th dose to ensure optimum protection develops before the onset of winter, when meningococcal disease is most prevalent.
"The clinical trials show that for young babies there is an increased immune response following a 4th dose of the MeNZB vaccine," she says. "This is important because of the high disease risk for this age group.”
The Ministry is also recommending about 3500 babies are given priority and receive their 4th dose early. These are babies who received their 3rd dose of the MeNZB vaccine before they were 21 weeks old (five months). They will be contacted by their medical practice so an appointment can be made for a 4th dose.
Dr O'Hallahan says: "Young babies are different in the way they respond to immunisation. It is common for babies to need an extra dose of vaccine as part of their scheduled childhood immunisations, in order to gain good protection against diseases. Babies are also the most at risk group for meningococcal disease.
“It is extremely important for parents to be aware that meningococcal disease is a risk for their child and that immunisation provides the best protection available against the epidemic strain of disease in New Zealand. Meningococcal disease is more prevalent in babies during their first 18 months of life and can have tragic consequences,"she says.
“Early indications show the vaccine is providing a good level of protection for those fully vaccinated, so it is important babies are vaccinated as early as possible once they are six weeks old.
“Older children and young people need three doses of the vaccine about six weeks apart. There are no plans to introduce a 4th dose for older age groups,” Dr O’Hallahan says.
Questions and Answers
Why is a 4th dose necessary for babies?
An extra dose of a vaccine is common for babies because they have a more immature immune system. Data on the administration of a 4th MeNZB vaccine shows a clear improvement in response rate for babies.
Data from the clinical trials using a schedule of three doses of MeNZB given concurrently with the routine schedule for infants, and with an interval of six weeks for older age groups, demonstrated that 55 percent of infants (enrolled at six to ten weeks), 74 percent of older infants (enrolled at six to eight months), 75 percent of toddlers (enrolled at 16 to 24 months), 76 percent of children (enrolled at eight to twelve years), and 93 percent of adults developed a four-fold rise (compared with pre-vaccination values) in serum bactericidal antibody titres, four to six weeks after the 3rd dose.
Additional data, from extension studies, on the administration of a 4th MeNZB vaccine showed a clear increase in response rate (four-fold rise) as would be expected with a primary course that consists of four doses in the first year of life. In recognition of the lower initial antibody rises in young infants this group is expected to have the greatest gains in further protection from a 4th dose.
How will the 4th dose be introduced?
The 4th dose will be incorporated into the Meningococcal B Immunisation Programme in January 2006 and will become routine for all babies who begin their MeNZB vaccinations under six months old.
How will parents know when their
baby needs its 4th dose?
Their families/guardians will be contacted by the medical practice that administered the baby's 3rd MeNZB dose to make an appointment for the 4th dose. The timing of this dose may vary depending on when the baby received their three doses
Why will some babies
receive the 4th dose early?
The recommendation for an early 4th dose for some babies comes after two cases of the epidemic strain of meningococcal disease in babies who received three doses before they were 21 weeks old. Neither baby was admitted to intensive care and they were both discharged from hospital after relatively short stays. The Ministry sought international advice on these two cases and it was recommended that, as a precautionary measure, a 4th dose should be offered early to those babies who received their 3rd dose before they were 21 weeks old. This affects a small number of vaccinated babies.
What is the Ministry
of Health’s advice regarding dose intervals for babies aged
under six months?
In November the Ministry updated its advice on immunising babies under six months old. For babies aged under six months it is recommended that the MeNZB vaccine doses be administered at six weeks old, three months old (not less than 13 weeks of age) five months old (not less than 21 weeks of age), aligned with the childhood immunisation schedule vaccines. The 4th MeNZB dose should be given to babies at least 10 months old, and a minimum of four months after their 3rd dose. This is to ensure the vaccine stimulates the optimum immune response as recorded in the clinical trials, while offering protection as early as possible. Babies are the group at highest risk of group B meningococcal disease.
How many babies are eligible
for a 4th dose?
By 20 January 2006 about 9000 babies who started their immunisation under six months old are expected to be due for a 4th dose.
Up to 27 November 2005 more than 2.87 million doses of the MeNZB vaccine were recorded on the National Immunisation Register. More than one million children and young people have received their 1st dose.
Is the vaccine proving effective in reducing
cases of the epidemic strain of meningococcal disease?
There are early and promising indications that the MeNZB vaccine is having an impact on reducing the number of epidemic strain meningococcal disease cases. This early indication comes from reviewing what has happened in the Counties Manukau District Health Board region where the programme first began.
Preliminary data, based on a relatively short timeframe and a population of 160,000, shows from January to November 2005 there were three cases of epidemic-strain meningococcal disease in those aged six weeks to four years old in the Counties Manukau and eastern corridor of Auckland DHBs. This compares to 20 cases for the same period in 2004, 22 cases for 2003, 19 cases for 2002 and 32 cases for the same period in 2001.
the Meningococcal B Immunisation Programme end?
The Meningococcal B Immunisation Programme was implemented as a mass rapid response immunisation campaign. That mass immunisation campaign ends on 30 June 2006.
Will any vaccine be available after 30 June 2006?
Everyone should aim to complete all three MeNZB doses by 30 June 2006. To do this they should try to receive their first dose by 1 March 2006. However, the MeNZB vaccine will still be available for all those aged 6 weeks to 19 years until 31 December 2006 to allow them to complete their vaccinations.
It is expected that the vaccine will continue to be available for babies and children under five years until further notice. New babies should get the MeNZB vaccine with their childhood immunisations.
Is it too late to start
It is not too late to begin. Immunisation with MeNZB is free from your local doctor or nurse. Older children and young people need three doses about six weeks apart.