Before the introduction of the MMR vaccine, all three diseases were extremely common. The majority of people had them at some point, usually as children. Although many people survived without long-term effects, others were left with serious disabilities and some children died. Complications of measles include fatal pneumonia and encephalitis (inflammation of the brain). In the year before a vaccine was introduced, 99 people died from measles complications. Mumps can cause deafness and meningitis, and in the past rubella caused many babies to be born with serious abnormalities.
A first dose of the MMR vaccine is given at 12-13 months in the UK schedule. The vaccine is not given earlier than this because studies have shown it does not work well in children under 1 year of age. A booster dose is given at 3 years and 4 months. There is also a catch-up programme for children and teenagers aged 10-16 who missed out on the MMR vaccine as babies.
There are now a large number of studies that show no evidence at all of any link between the MMR vaccine and autism. In the short film below, experts say why they believe there is no link. See 'Is the vaccine safe?' towards the bottom of this page for a full list of studies.
The vaccine contains live, but weakened (attenuated) strains of the measles, mumps and rubella viruses.
The measles and mumps virus strains are grown on a culture which contains chick embryo cells (see more information about the use of animal cell-lines to grow viruses for vaccines). The viruses are not grown on eggs. This means that there is not enough egg protein in the MMR vaccine to cause allergic reactions, so children with severe egg allergies can safely receive the MMR. In the past, people with an egg allergy were advised not to receive the MMR vaccine, but advice on this changed more than ten years ago. In the short film below, Professor Simon Dobson explains how we know that there is no increased risk of reactions to the MMR vaccine in children who are allergic to eggs.
The rubella virus strain is grown in the laboratory using human cell-lines. See more information on human cell-lines.
There are two MMR vaccines recommended for use in the UK. Both may contain traces of neomycin, an antibiotic used in the production process. See more information on antibiotics in vaccines.
One of the MMR vaccines used in the UK (MMR VaxPro) contains gelatine derived from pigs. The other MMR vaccine used in the UK (Priorix) does not contain gelatine. See more information on gelatine in vaccines.
The vaccine may also contain tiny amounts of products used during the manufacturing process. Click on the links to see more information on our Ingredients page:
The MMR vaccines used in the UK do not contain the preservative thiomersal (mercury).
The three viruses in the MMR act over different time periods. The following side effects are common but not serious:
More serious side effects are rare:
You should consult your doctor if these reactions happen after vaccination. This is mainly to check that it is the vaccine causing the symptoms, and not some unrelated disease. Symptoms such as fits can be very worrying for parents, but there is no evidence of long-term effects. Children can normally safely receive vaccines in the future.
As with any vaccine, medicine or food, there is a very small chance of a severe allergic reaction (anaphylaxis). Anaphylaxis is different from less severe allergic reactions because it causes life-threatening breathing and/or circulation problems. It is always serious but can be treated with adrenaline. In the UK between 1997 and 2003 there were a total of 130 reports of anaphylaxis following ALL immunisations, but all of these people survived. Around 117 million doses of vaccines were given in the UK during this period, making the overall rate around 1 in 900,000. Depending on the cause of the reaction, and following expert guidance, the person may be able to have vaccinations in the future.
Reactions listed under ‘possible side effects’ or ‘adverse events’ on vaccine product information sheets may not all be directly linked to the vaccine. See Vaccine side effects and adverse reactions for more information on why this is the case.
See more information on the monitoring of vaccine safety.
In the short film below, experts talk about measles and its complications, and the importance of the MMR vaccine.
Sarah Clow fell seriously ill with measles when she was five and was left with lasting disabilities including deafness, partial sight and learning difficulties. Her mother Audrey talks about the impact this has had on Sarah and the whole family. Thanks to Rockhopper TV for the original footage.
Sarah was not vaccinated against measles as a child because she had had eczema. Advice on this has now changed; current advice is that children with eczema can safely receive the MMR vaccine and other vaccines.
Sarah Walton caught measles when she was 11 months old, and at the time recovered well. Twenty four years later, however, she fell ill and was diagnosed with subacute sclerosing panencephalitis (SSPE). SSPE is a persistent viral infection, a rare but devastating complication of measles which leads to a progressive destruction of the central nervous system. It causes dementia, loss of motor control, epilepsy and eventually death. In this video Sarah’s mother Jo talks about the impact that SSPE has had on Sarah and the people around her.
For more information about the egg allergy issues raised in the video, see the 'Ingredients' section above.
There are now a large number of studies that show no evidence at all of any link between the MMR vaccine and autism. Autism is a developmental disorder which is usually diagnosed in pre-school children. The original research which suggested a link has now been discredited. The National Autistic Society has issued a statement stating that the weight of evidence points to the fact that ‘there is no statistically significant link between the MMR vaccine and autism’.
Below is a list of studies and their findings. Click on the links to view the abstracts (summaries) of the scientific papers: