Explanation

Immunisation (also called vaccination) is protection against certain diseases. The vaccines are given to you as injections by your doctor. Immunisation improves your immune system so that it can recognise these diseases immediately, before they can attack your body and make you ill. Sometimes, you will have more than one injection - you will have one when you are a baby and then others, called boosters, when you are older.

Why do I need one?

You need to have immunisation to protect you from some serious diseases that could make you very ill or even kill you. Everyone has these immunisations when they are kids. You will have most of them before you are 4 years old, so you probably won't even remember having them.

When you are older, you will need a booster for some of the immunisations you had as a baby. For example, you will need a booster for tetanus, diphtheria and polio when you are between 13 and 18 years old. Luckily though, the boosters for these illnesses all come in one injection, so you don't need to have three separate ones!

If lots of people start getting a new disease, like swine flu, you may need to have immunisation against that, too.

Also, if you are a girl, you will probably have an immunisation against human papillomavirus (HPV) when you are between 12 and 18 years old. This is a new vaccine that stops you getting cervical cancer when you are older. Your doctor will tell you all about this vaccine.

If you travel to other parts of the world, you may need to have other immunisations to protect you from diseases that you could get in the place you are going to. If you are going abroad, your doctor will tell you if you need to have any vaccinations before you go.

What happens before I have it?

Usually, you don't need to do anything to prepare before an immunisation. You just go along to your GP's surgery and your nurse or doctor will give you the vaccination.

How is it done?

Most immunisations are given as injections, usually into your thigh or the top of your arm.

Your doctor or nurse will wipe your skin to make it nice and clean, and will then inject the vaccine. This only takes a few seconds.

Afterwards, the doctor or nurse will put a plaster or a pad of cotton wool over the place where you had the injection, to help the tiny wound heal sooner and to stop any bleeding.

Some immunisations don't come as injections, you have them on a cube of sugar or dripped directly into your mouth instead - sweet!

Will it hurt?

Immunisations don't usually hurt, but they may feel a bit ticklish.

Could it cause any problems afterwards?

Most kids have no problems afterwards. You may get a sore arm or a mild fever, but this will soon go.

It's possible that you could be allergic to the vaccine, so if you feel unwell after any immunisation you should tell your doctor immediately.

Should I ever refuse immunisation?

If you are supposed to be having an immunisation and you are ill, like if you have a fever for example, you shouldn't have it. Tell your doctor what's wrong, and you can go and have the vaccine another time when you feel better.

You should also tell your doctor or nurse if you have ever had a bad reaction to an immunisation, or if you have any allergies, especially if you are allergic to eggs or to any other medicines.

You should not have vaccines for TB (the BCG vaccine) or for measles, mumps and rubella (the MMR vaccine) if:

you are having chemotherapy, or have had it in the last 6 months

you have had an organ or bone marrow transplant in the last 6 months or are taking immunosuppressant

you are taking steroids or have a weakened immune system

This is because these vaccines have tiny amounts of live cells of the actual disease inside them. They are called live vaccines. They can be very dangerous to have if you are not healthy.

If you are worried about any immunisation you are going to have, talk to your doctor about it first, and he or she can reassure you. You will only be given vaccines that are safe for YOU.

What happens next?

You can go home after you have had your immunisation. You will now be protected from the disease you've been immunised against, so you won't get it!

If you need to come back for a booster in the future, your doctor will let you know just before you are due to have it.

What if I have any more questions?

If you have any other questions, you can ask your doctor, or chat to other people about