When should my child have the MMR jab?

Children will ideally have the MMR vaccination just after their first birthday and the second dose is usually given when they are over three years old and certainly before they start school and start to mingle with other children who might have the infection.

The vaccination is free on the NHS – you can just call to make an appointment for your child with your GP or practice nurse.

Are there any adverse reactions that should I expect once my child has had the MMR vaccination?

Any vaccination can cause mild side effects, such as soreness at the site of injection. Injection site reactions do not happen often after MMR. The reactions that do happen occur when the viruses in the vaccine start to act and this happens at different times. The following side effects can come after the first dose:

• Six to ten days after the immunisation, about one in ten children may develop a mild fever and some develop a measles-like rash and go off their food for two or three days. This can happen when the measles part of the vaccine starts to work, and is normal. Your child doesn't have real measles and isn't infectious.
• About one in every 1000 immunised children may have a fit caused by a fever. This is called a "febrile convulsion", and can be caused by any fever. If you know this could be a side effect, you can look out for the fever and treat it with infant paracetamol or ibuprofen. If a child who has not been immunised gets measles, they are five times more likely to develop a fever and have a fit.
• Rarely, children may get mumps-like symptoms (fever and swollen glands) about two to three weeks after their immunisation as the mumps part of the vaccine starts to work –  this is not actually mumps and is not infectious.
• Very rarely, children may get a rash of small bruise-like spots in the six weeks after the vaccination. This is usually caused by the measles or rubella parts of the vaccine. If you see spots like these, take your child to the doctor to be checked. They will tell you how to deal with the rash.
• Less than one child in a million develops encephalitis (inflammation of the brain) after MMR vaccine, but other infections can also cause encephalitis. However, if a child catches measles, the chance of developing encephalitis is about one in 1000. Your doctor or practice nurse will be able to discuss these issues in more detail.

If my child has a reaction to the vaccine, how should I treat it?

Give your child infant paracetamol/ibuprofen and if symptoms persist take your child to the doctor or call NHS Direct on 0845 4647. If your child does suffer from a rash of small bruise-like spots, take your child to the doctor to be checked in the first instance.