What is immunisation?

Active immunisation is the use of vaccines to protect against particular diseases caused by bacteria or viruses.

What are vaccines?

Vaccines contain weakened, dead or (usually) fragmented viruses and/or bacteria that are responsible for some serious diseases. The body sees these fragments as foreign and develops an immune response (immunity) against them, without exposing the vaccinee (person receiving the vaccine) to the disease.

How does immunity work?

When a virus or bacteria enters our body, our immune system develops an immune response, which includes antibodies specifically against the virus or bacteria, to fight it. The first time an organism enters the body, the immune system is not ready and it takes some time to make antibodies. During this time we may become ill; however, if our immune system including the antibodies can control the organism, we recover.

After infection, the immune system retains a memory of the infecting organism that attacked us, and if it enters our body again it is usually controlled before we become ill. Active immunisation using vaccines works in the same way - without us having to have the disease first.

Does my child need immunising?

Doctors worldwide believe it is essential that children receive a number of immunisations to prevent them getting serious childhood infections. Also, it is important for the community that as many children as possible are immunised, to prevent the spread of these diseases to other members of the community who may not be able to be vaccinated for various reasons.

In countries where immunisation is given to a very high number of people, the diseases can be controlled or eliminated from the population and the number of children who die of infectious diseases is dramatically reduced. Even if most of these diseases are now less common, they can come back at any time. New Zealand's immunisation rate is very low compared to many countries.

Where else does immunity come from?

We get immunity from many diseases by having them. However, that also means we usually get sick first. In some cases this is not serious, in others, the risk of serious illness is too high. That is why we vaccinate against some of the most serious diseases. Also, mothers pass on many antibodies to their babies both before they are born as well as in the breastmilk, if they breastfeed their babies.

Antibodies from the mother only last from weeks to months. Once they have gone, the child is unprotected from these infections. Breastfeeding does not protect a baby against many serious illnesses such as whooping cough (pertussis). It does, however, protect against some types of diarrhoea, vomiting, coughs and colds.

Is immunisation safe?

Vaccines must go through many tests before they can be used. The vaccines used in New Zealand have been proven to have excellent safety profiles and to be highly effective. Studies have shown that if all doses of vaccines are given properly they will protect 80% to 95% of the children who are immunised.

A number of children will have a minor reaction to immunisation. Serious reactions such as severe allergic reactions can happen, but are very rare. Your doctor is trained to handle such problems.

Some children who have been immunised may still become ill with the disease, but usually their illness is much less serious.

The risk from disease is far greater than the risk from immunisation. For example, one child in a million may get swelling of the brain after measles vaccination, while one in a thousand develops swelling of the brain from measles itself: of those, 15% will die and another 25% will have brain damage.

When should my child not be immunised?

If your child is having some medical treatments, has a serious disease or lives with someone with a severe disease, has an immune system that is not working properly or has had severe allergic reactions to immunisations before, or has recently had other vaccinations or blood treatments, immunisation may not be advisable.

Talk to your doctor. If the child has a cold or is a little unwell on the day of immunisation they can still be safely immunised. If they have a high temperature (over 38 degrees) or are very unwell, it may be better to delay the vaccination for a day or two.

What vaccines does my child need?

The New Zealand immunisation schedule from 1 July 2011 is:

• Ages 6 weeks, 3 months, 5 months: Diphtheria - Tetanus - acellular Pertussis - Inactivated Polio - Haemophilus influenzae type b [Hib] - Hepatitis B (DTaP-IPV-Hib-HepB) + Pneumococcal disease vaccine (PCV).
• Age 15 months: Measles - Mumps - Rubella (MMR) + Haemophilus influenzae type b (Hib) + Pneumococcal disease vaccine (PCV).
• Age 4-5 years prior to schol entry: Measles - Mumps - Rubella (MMR) + Diphtheria - Tetanus - acellular Pertussis - Inactivated Polio (DTaP-IPV).
• Age 11 years [school year 7]: adult Tetanus - Diphtheria - acellular Pertussis (Tdap).
• Age 12 years [school year 8]: HPV (human papillomavirus) immunisation, 3 doses over 6 months (offered to girls only). Also funded until age 20 years in females.
• Age 45 and 65 years (boosters): adult Tetanus - Diphtheria (Td) boosters at 45 and 65 years of age or after some injuries if it is more than five years since the last booster - check with your local medical centre (a charge may apply for boosters).
• Additional vaccines for special groups are listed further below.

# Note:  Vaccines marked with # may not be in use until later in the year (2011) depending on current stocks. For pneumococcal disease, infants may therefore be given the previous vaccine, Prevenar 7, instead of Synflorix; a child can start their course on Prevenar 7 and continue or complete it with Synflorix. For Haemophilus influenzae type B (Hib), children may receive the previous vaccine, Hiberix, as the new vaccine, ActHIB, may not be in use until later in the year.

** Influenza vaccination is currently funded for adults over 65 years, pregnant women, those under 65 with some medical conditions, and children from age 6 months with certain medical conditions - see Influenza vaccination for details. (Other people can also have the vaccine but will have to pay for it).

Also on schedule: HPV (human papillomavirus) vaccine Gardasil is offered to girls in school year 8 (age 12 years). It is a course of 3 doses over 6 months. More about the HPV vaccine programme is given further below.

Vaccine key
DTaP = Diphtheria, Tetanus, acellular Pertussis - child
IPV = Inactivated Polio Vaccine
Hib = Haemophilus influenzae type b
HepB = Hepatitis B
PCV = Pneumococcal
MMR = Measles, Mumps, Rubella
Tdap = Tetanus, Diphtheria, accellular Pertussis - adult
Td = Tetanus-Diphtheria - adult [children 7 years and older, adults]
ADT = Adsorbed Diphtheria, Tetanus. 

Special groups requiring additional vaccines:

• Premature babies: details from your doctor or IMAC.
• Birth: BCG vaccine for babies "at risk" for tuberculosis (TB). This is currently defined as babies living in households with people who have, or have had tuberculosis (TB); where one parent or household member has lived for 6 months or more (in the last 5 years) in a country where TB is common; or the infant during their first 5 years will be living for 3 months or more in a country where TB is common. 
• Babies of hepatitis-B carrier mothers need an extra dose of hepatitis B vaccine plus hepatitis B immunoglobulin at birth. 
• Household and sexual contacts of hepatitis B carriers require hepatitis B vaccine.
• Women of childbearing age who are susceptible to rubella (German measles) should be offered MMR vaccine.
• Children and adults before and after splenectomy (surgery to remove the spleen) or with non-functioning spleens will be eligible to receive pneumococcal, Hib and meningococcal vaccines.

Infanrix-hexa

The Infanrix-hexa vaccine was introduced to the vaccination schedule in 2008, and it replaced the former two vaccines (Infanrix-IPV and Comvax). Infanrix-hexa thus provides the diphtheria, tetanus, acellular pertussis, inactivated polio vaccine, Haemophilus influenzae type b and hepatitis B dose (given at ages 6 weeks, 3 months and 5 months).

Pneumococcal vaccine

The funded pneumococcal vaccine changed, from 1 July 2011, from Prevenar 7 to Synflorix (but Synflorix may not be in use until later in 2011, depending on vaccine stocks). 

A pneumoccocal vaccine was added to the immunisation schedule in 2008, to help protect young children against the most common strains of Streptococcus pneumoniae bacteria that cause severe pneumococcal disease.

Children who are eligible for the High risk immunisation programme receive a different pneumococcal vaccine, Prevenar 13, which covers more strains of the bacteria than Synflorix or Prevenar 7. Children in this programme usually then receive another type of pneumococcal vaccine, Pneumovax 23, which is also suitable for use in adults.

Parents can request Prevenar 13 (rather than Synflorix) for their child, but Prevenar 13 will not be funded (free) unless their child is eligible for the High risk immunisation programme.

See our topic on pneumococcal disease for more detailed information, including about the High risk immunisation programme.

HPV immunisation

From 2011, the human papillomavirus (HPV) vaccine is offered to girls in school year 8 (age 12 years). The HPV vaccination programme was introduced in 2008. HPV is a sexually transmitted infection linked to the development of cervical cancer. HPV also causes genital warts.

HPV immunisation requires 3 doses, given over 6 months. The funded HPV vaccine is Gardasil. Females from age 12 years to their 20th birthday can have the funded vaccine, but they must have had their first dose before their 20th birthday. The vaccine is offered through participating schools, or can also be obtained through GPs, health centres and Family Planning clinics.

Gardasil is approved for use in New Zealand for females aged 9-45 years and males aged 9-15 years. Males, and females over 20 years, can pay to have the vaccine (discuss with your doctor). There is also a second vaccine approved for use in New Zealand, Cervarix, but this is not funded. More information on HPV and HPV vaccines.

Meningococcal B programme now ended

There is currently no meningococcal vaccine included on the schedule. However, meningococcal vaccines may still be recommended for those at particular risk, and may be funded in some circumstances. Meningococcal disease is a bacterial infection causing severe illnesses, including meningitis (an infection of membranes that cover the brain) and septicaemia (a serious infection in the blood).

A meningococcal B immunisation programme was previously introduced in response to an epidemic in New Zealand of a meningococcal B strain (vaccine MeNZB was developed for this purpose). The special immunisation programme ran from 2004 to 2008, and was discontinued after disease rates had been reduced substantially. The last phase of the meningococcal B programme, which was for immunisation for people with a high medical risk, ended in March 2011.

People who want their child to receive a meningococcal vaccination should discuss this with their doctor. Young people going to live in hostel-type accommodation may also want to consider having a meningococcal C vaccine, though this is not funded.

What are these diseases?

Diphtheria
Diphtheria is a bacterial infection which affects the throat, making it hard to swallow and breathe. Children can become paralysed, develop heart failure or suffocate. The illness is now rare because of immunisation, but the bacteria is still around in some countries.

Tetanus
Tetanus is a bacterial infection which attacks the nerves and causes muscles to become tense and stiff. It lives in the soil and is picked up through skin wounds. If the breathing muscles are affected, it is serious and can be fatal. It is also now rare.

Whooping cough (pertussis)
Whooping cough, a serious bacterial infection of the chest, causes painful, difficult coughing. The cough is so severe that breathing is difficult and the child may vomit. Most children are well between coughing fits, but some get pneumonia, fits, coma, inflammation of the brain and brain damage. It is usually more severe in younger children, with young babies at highest risk of severe complications and death. Whooping cough is still a common disease and there are outbreaks every three to five years.

From February 2006, 11-year-olds have received a booster of the whooping cough (pertussis) vaccine added to the diphtheria, tetanus vaccine dose (instead of at age 15 months as was previously offered). This change was made as research shows adolescents to be at risk both of developing whooping cough and becoming carriers of the disease.

After the initial 3 doses of vaccine in infancy, two booster doses are given at a later stage, which maintains protection for a longer period. Receiving the second booster dose at 11 years thus offers protection throughout adolescence. Younger children, who no longer receive the dose at 15 months, have their immunity boosted by the dose at age 4 years.

Hepatitis B
Hepatitis B virus infects the liver and causes fever, nausea, tiredness, dark urine and jaundice. Children usually only have mild symptoms but they are likely to become carriers and are at risk of liver disease and liver cancer later in life. Symptoms are usually more serious in adults.

Hepatitis is common in New Zealand, particularly among Maori, Pacific Islanders and some Asian groups. Each year, in New Zealand, about 100 people who carry the virus die from these illnesses. Children of mothers with hepatitis B must be vaccinated at birth.

Poliomyelitis
Polio is a viral infection of the nerves and it can paralyse different parts of the body, leaving the person permanently weakened. Because of vaccination, it is now rare in most countries, but is still found in some countries and can be passed on by travellers. Travellers should be aware there has been a resurgence in some countries which were previously polio-free, following false rumours that the vaccine spread HIV and caused infertility.

From January 2008 the polio dose was removed for 11-year-olds (they still receive the diphtheria-tetanus-acellular pertussis vaccine at this age). This is due to an earlier change to the schedule (in 2002) which means children receive their fourth polio dose at age four years.

Haemophilus influenzae type b (Hib)
Hib is a serious bacterial infection that can cause inflammation of the lining of the brain (meningitis), throat (epiglottitis) or many other conditions, including pneumonia. It has a death rate of about 3% for meningitis: many children who survive it have permanent nerve or brain damage. Before vaccination started in 1994, one in every 350 children under five became seriously ill with Hib.

From February 2006 the Haemophilus influenzae type b (Hib) vaccine has been used with the measles, mumps, rubella (MMR) vaccine at age 15 months.

Measles
Measles is a highly contagious common childhood disease that causes fever, runny nose, cough, rash, and eye infections. Possible complications from measles include diarrhoea (and possible dehydration), ear infections, fits, pneumonia, and brain inflammation. Pneumonia can be fatal, and brain inflammation can lead to permanent brain damage or death.

Mumps
Mumps is also very common and causes fever, headache and swelling of the glands around the face. In adults and teenagers mumps may cause swelling of the testes and ovaries. It often causes swelling of the brain, but most children recover without a problem. Very rarely, it causes deafness or death.

Rubella
Rubella or German measles is common and is only a problem if women are infected in the first three months of pregnancy when it can cause serious damage to the developing baby. Rubella is usually a mild illness in children, but in teenagers and adults can cause swollen glands, joint pain and a rash. Rarely, it may cause serious illness.

Tuberculosis (TB)
TB bacteria can infect any part of the body. There are often no symptoms at first and the infection can hide in the body and be stirred up again at any time. About 5% of infected people get lung or other problems. The condition is worse in children, the elderly or people with other diseases.

Tuberculosis is more common in Maori and immigrants from Southeast Asia and the Pacific Islands. Worldwide there is currently a resurgence of TB. Routine immunisation is no longer considered necessary but is given to high-risk infants.

What can I expect after immunisation?

The most common side effects are injection site pain and redness, sometimes a mild fever. Mostly, children will need reassurance and lots of cuddles. If they are hot, put them in light clothing and give them lots of fluids. Cool flannels over the injection site may help.

If your child has any unusual reactions or you are concerned, ring your doctor or practice nurse.

Does my child need an immunisation certificate?

All children born after January 1995 need an immunisation certificate. This lists the vaccinations recommended for all New Zealand children and shows whether your child has completed the full series. Your nurse or doctor will sign a certificate when the immunisations are completed at around 15 months.

A second certificate is issued once your child has had their follow up immunisations at around 4 to 5 years. If you decline immunisation the certificate can be signed by your nurse or doctor at any time.

Your child's early childhood centre, kohanga reo or primary school will need to see the certificate and record the information in a register. This register is checked by a Medical Officer of Health if there is an outbreak of disease in your area.

Children who have not been immunised will be offered immunisation. Non-immunised children may be asked to stay at home until the disease has gone, to help stop it spreading.

Further information and support

It is important that you fully understand the risks and benefits of immunisation, and discuss any questions or doubts you have with your doctor, Plunket nurse, local immunisation coordinator or the public health unit at your local public hospital.

Full information on all vaccines is available from the following groups and organisations:

• NZ Ministry of Health (MOH) Manatu Hauora - MOH website Immunisation section
• Immunisation Advisory Centre (IMAC - see further below for contact details).

Original content provided by everybody. Source material from IMAC, the Ministry of Health, and the Ministry of Health Immunisation Handbook 2011. Updated by everybody, July 2011.