Immunisation - childhood

About childhood immunisations

Immunity is your body’s defence system against infectious diseases. Babies are born with some immunity (to bacteria and viruses that cover their skin, nose, throat and intestines) that will last throughout their lifetime. This is called innate or non-specific immunity.

Your child’s body also needs to learn and remember how to develop his or her own antibodies (proteins produced by the immune system) to fight against specific bacteria and viruses as he or she comes into contact with them. This is called acquired immunity. There are two different ways that your child can acquire immunity.

  • Passive immunity. This is protection (from antibodies) that is passed from one person to another. This is usually from mother to baby across the placenta but sometimes from the transfusion of blood. Passive immunity is temporary and will only last for a few weeks or months.
  • Active immunity. This is protection that is produced by your child’s immune system. It usually develops from the disease itself or by vaccination.

Vaccines contain a small part of the bacteria or virus that causes a disease. This stimulates your child’s immune system, resulting in the production of antibodies in the same way as an infection, but without causing a full-blown disease. Vaccines are a safe way to ensure your child develops his or her own antibodies to a particular infection. Vaccines are made using:

  • dead viruses or bacteria
  • inactivated toxin from a virus or bacterium
  • a weakened form of a live virus or bacterium (called a live vaccine)
  • parts of a virus or bacterium, but not the whole organism (called component vaccine)

Animation - How bacterial vaccines work

Why immunise?

All of the infections that are in the childhood immunisation programme can develop into serious illnesses and have the potential to cause disability or death. Immunising your child means that he or she is protected from these serious diseases and their potentially devastating effects. Many of the diseases that your child can be immunised against have no cure so vaccination can prevent any unnecessary illness.

If most children are immunised, then the risk of infection in the community is significantly reduced and even unvaccinated children are at much less risk of catching the disease. This is called 'herd immunity'.

Some people argue that there is no longer any need to immunise children. Diseases such as polio, for example, are now almost never seen in the UK. However, these diseases haven't yet disappeared and if your child comes into contact with someone with the disease, either in the UK or abroad, then he or she is likely to catch it. If more people choose not to immunise their children, then the number of children at risk of catching a disease will increase and outbreaks of the disease will occur. In the UK, many diseases are rarely seen because of the high rate of childhood immunisation.

Immunisations offered in the UK

Vaccines given routinely to children in the UK protect against:

  • diphtheria
  • tetanus
  • pertussis (whooping cough)
  • polio
  • Haemophilus influenzae type B (Hib)
  • meningitis C
  • pneumococcal infection (eg pneumonia, meningitis and septicaemia)
  • measles
  • mumps
  • rubella (German measles)
  • human papilloma virus (HPV)

The following vaccines are given selectively.

  • Tuberculosis (TB). The Bacillus Calmette-Guérin (BCG) vaccine is now given to children in areas with a high rate of TB or who have a parent or grandparent from a country with a high rate of TB.
  • Hepatitis B. Children who live with parents who have hepatitis B or have regular blood transfusions should be vaccinated.
  • Chickenpox. A vaccine is recommended for children who have a family member whose immune system isn’t able to fight disease as well as it should, for example, if they have leukaemia or if they have a parent who’s having chemotherapy.

For some immunisations, your baby will need a course of vaccines to build up his or her defences. Booster vaccines are needed to 'top up' immunity for pre-school children and teenagers.

Immunisations explained

DTaP/IPV/Hib vaccine

The DTaP/IPV/Hib vaccine protects babies against five different diseases.

  • D – diphtheria
  • T – tetanus
  • aP – acellular pertussis (whooping cough)
  • IPV – polio
  • Hib – Haemophilus influenzae type B

Pneumococcal conjugate vaccine (PCV)

PCV protects against some strains of pneumococcal infection, which can cause diseases such as pneumonia, blood poisoning (septicaemia) and meningitis.

Meningococcal C (MenC) conjugate vaccine

The MenC vaccine protects against the bacterium that causes a severe form of blood poisoning (septicaemia) and/or meningitis. Your child can have it at the same time as the DTaP/IPV/Hib vaccine. It’s given as a separate injection.

Measles/mumps/rubella (MMR) vaccine

The MMR vaccine protects against measles, mumps and rubella. Stories in the media have raised concerns about a possible link between the MMR vaccine, autism and bowel disease. However, there is a great deal of scientific evidence from around the world that shows no connection between these conditions and the MMR vaccine. There’s also a lot of research to prove the safety and effectiveness of the MMR vaccine.

Bacille Calmette-Guérin (BCG) vaccine

The BCG vaccine protects against tuberculosis.

Your child will have a skin test, called a Mantoux. If the reaction is positive, it suggests he or she already has immunity and will not need the BCG injection.

Hepatitis B vaccine

Hepatitis B vaccine is usually given only to those children who are most likely to catch the disease, such as those who have a parent with hepatitis B.

Human papilloma virus (HPV) vaccine

Girls aged 12 to 13 are now routinely given the HPV vaccine. It protects against the two main viruses that cause cervical cancer.

UK immunisation schedule

The following table shows when to immunise your child against each disease.

Age Vaccine Type of injection Stage of vaccine course
2 months DTaP/IPV/Hib 5-in-1 injection First dose
  PCV Single First dose
3 months DTaP/IPV/Hib 5-in-1 Second dose
  Men C Single First dose
4 months DTaP/IPV/Hib 5-in-1 Third dose
  Men C Single Second dose
  PCV Single Second dose
12 months Hib/Men C Single Booster
13 months MMR 3-in-1 First dose
  PCV Single Booster
3 years and 4 months to 5 years MMR 3-in-1 Booster
  DTaP/IPV 4-in-1 Booster
12 to 13 years (girls) HPV Single Three doses given over six months
13 to 18 years Td/IPV Single Booster

How are immunisations given?

Immunisations or vaccines are given by injection, usually into the muscle in the upper arm or thigh.

When to delay immunisation

If your child is in good health and due for immunisation, you shouldn't delay having a vaccine.

A vaccine won't be given if your child has a fever when the injection is due. The vaccine could worsen the fever. Also your child's current illness could make it difficult to identify any side-effects to the vaccine. Your GP or nurse will usually examine your child and re-arrange the appointment if your child is too unwell to have the injection.

If you have any concerns about a particular vaccine, talk to your GP, practice nurse or health visitor.

Your child won't be given live vaccines, such as MMR and BCG, if he or she:

  • has a weakened immune system because of a serious condition, such as HIV/AIDS, or because he or she is taking medicines that suppress his or her immune system
  • has had a serious allergic reaction to a previous dose of the vaccine or to antibiotics that may have been added to the vaccine

Speak to your GP if your child has any condition affecting his or her immune system.

Don't delay getting your child immunised if he or she:

  • has a minor illness, such as a cough or cold
  • has already had an illness similar to that covered by a combined vaccine (for example, if your child has had mumps, he or she should still have the MMR vaccine)
  • is being treated with antibiotics, topical steroids or replacement corticosteroids
  • was a premature or very small baby, or jaundiced after birth
  • is being breastfed or if the child’s mother is pregnant
  • has a stable neurological condition, such as cerebral palsy or Down’s syndrome
  • has asthma, hay fever or eczema
  • is over the immunisation age recommended in the schedule
  • has a family history of side-effects to a vaccine, inflammatory bowel disease or autism

Side-effects of immunisations

Side-effects are the unwanted but mostly mild and temporary effects of a successful immunisation. Side-effects of a vaccine may include:

  • some redness and swelling at the injection site
  • a raised temperature (above 37.5°C but below 39°C)
  • irritability

You can help to lower your child's temperature and relieve any discomfort by:

  • giving your child liquid paracetamol or ibuprofen – always read the patient information that comes with the medicine and if you have any questions, ask your pharmacist for advice
  • removing some clothes and blankets to keep them cool

Severe reactions

A severe reaction to a vaccine is very rare. You should seek urgent medical attention if your child:

  • has a very high temperature (over 39°C)
  • has a fit – this is called a febrile convulsion
  • develops a rash
  • finds it difficult to breathe
  • feels very lethargic
  • cries inconsolably which may be high-pitched and unusual

Is immunisation safe?

Health professionals recognise that routine immunisation is the best defence against potentially dangerous diseases and it’s a safe way to ensure protection. All vaccines must be thoroughly tested to make sure they are safe and effective. Once they have been licensed, their safety is continuously monitored and any side-effects that are discovered can be assessed further.

What happens if my child misses his or her booster dose of a vaccine?


Your child won't be fully protected if he or she hasn't received all the doses of a vaccine.


There are two major reasons for booster doses: to protect your child and to protect the entire population of children.

Having a booster 'tops up' the level of antibodies produced by your child in response to the particular vaccine. If your child hasn't received all the doses, his or her level of protection will be reduced. Pre-school boosters help to keep your child protected during their school years.

Also, having a high level of immunity among the general population (herd immunity) is vital to reduce the risk of spreading disease from person to person. The lower the herd immunity, the greater the risk of a disease outbreak.

If your child has missed an appointment and is late getting a booster dose, make an appointment as soon as possible. The gap advised to leave between having a vaccine and having the booster dose is the ideal amount of time, but the booster will still work if it's given later. You won't have to start the course of vaccines again.

Can my baby's immune system cope with receiving so many vaccines all at once?


Yes. The vaccines can't cause a full-blown illnesses, which means your baby's immune system can easily cope with them.


Some parents worry about the number of vaccines children receive these days. However, it has been estimated that a baby's immune system could respond to as many as 10,000 vaccines at any one time.

Your child’s immune system is constantly challenged by infections so there is no reason to think that a vaccine will damage his or her immune system.

If my child is ill, will he or she still be able to respond to a vaccine?


Yes, having an illness doesn't reduce your child's ability to respond to a vaccine.


Some parents may believe that giving a vaccine to a child who is ill may burden the immune system at a time when the child is already trying to fight off an infection. It's a common misconception that children who are ill will be less likely to respond to a vaccine, or more likely to get side-effects, as their immune system is compromised.

The response to a vaccine is the same in healthy children and those with mild or moderate illness. Your GP or nurse will usually suggest postponing the immunisation if your child is very ill, until your child is fully recovered. This is to ensure that symptoms of your child's current illness are not mistaken as side-effects of the vaccine.

Also, a common side-effect to any vaccine is a temperature. If your child has a high temperature or fever at the time the injection is due, the vaccine is often delayed to avoid making it worse.

Why are girls being offered the cervical cancer vaccine at such a young age?


The human papilloma virus (HPV) vaccine is most effective when it's given before a girl becomes sexually active.


The HPV vaccine protects against two specific types of HPV, which are the most likely to cause cervical cancer. These are HPV types 16 and 18, which cause around seven out of 10 cancers of the cervix. The vaccine doesn't provide protection against any other types of HPV.

The HPV vaccine is given to girls aged 12 and 13. This is because the vaccine is more effective if it's given to girls before they become sexually active. If your child is sexually active before she has the vaccine, she may already have HPV and the vaccine won’t help to clear it up.