In 1998, research by Wakefield et al' suggested a possible link between the MMR vaccine, inflammatory bowel disease and autism. Sensational media reporting of these findings led to concerns amongst parents about whether they should give their child the MMR (measles, mumps and rubella) vaccine. Unsure of the right decision to make, several parents choose not to immunise their children, which resulted in a significant increase in the number of cases of measles and mumps.
Since 1998, the research findings by Wakefield et al' have been contested by many other scientific studies, which have produced good scientific evidence to suggest there is not a link between MMR, inflammatory bowel disease and autism (see 'Resources & Information' section: Medical Research on MMR autism and bowel disease, and other safety issues). As a consequence, some parents we interviewed had few concerns about giving their child MMR.
The overwhelming majority of parents believe in immunisation for their children. We have however included here the views of a few parents who do not believe immunisation is right for their own child based on their personal beliefs. Their views represent a small proportion of the population.
Initial concerns did still exist amongst many parents when making their decisions about their child's MMR, but after gathering information and weighing up the risks, they felt reassured enough to go ahead with it (see 'Information for making decisions' and 'Weighing up the risks'). Some of these parents found it very difficult to make a decision and were worried for a long time before they made a final decision.
It is absolutely right and normal that parents are concerned about the optimal health of their children and it is important that parents seek reliable scientific evidence on which to base their decisions and there is now a mass of this information available (see Resources & Information' section).
A few parents did not find enough reassurance and decided that MMR was not the right decision for their child and chose single vaccines or not to immunise (see 'Deciding not to give my child MMR').
Some parents who had initially been concerned that after having MMR, their child might develop inflammatory bowel disease or autism had felt reassured after learning more about MMR and how autism develops, for example that MMR has been used in the USA since the early 1970s and reported serious reactions have been very rare (see 'Deciding to give my child MMR').
A few parents had been concerned that their child's immune system was already compromised in some way and that MMR may make the situation worse, for example if their child was premature, or already had allergies or bowel problems. (See Questions 32, 9 and 10 in 'Q&A' section.) After getting advice from health professionals, these parents felt reassured enough to give their child MMR.
Every parent should have access to a trained health professional to chat about their concerns, the risks of catching the diseases and the benefits and potential risks of immunisation for their own child, and the population in general. In addition to their GP, health visitor or practice nurse, there is also an immunisation advisor in each local health protection unit, whom parents can talk to about their child's immunisations. (See Health Protection Agency website for details about local contacts.)
A few parents were worried about whether they should give their child MMR because he/she had an egg allergy. There is no evidence to suggest that children with egg allergies should not be given MMR and it can be given in a hospital setting if parents are concerned. (See Question 36 in the Q&A' section.)
Most parents who had given their child the MMR pre-school booster, had had less concern making a decision, largely because their child had not had a reaction to the first dose of MMR.
A very small number of parents were anxious that the previous reactions that their other children had, which they personally believed were triggered by MMR, might occur again. Research studies since 1998 have produced good scientific evidence to suggest there is not a link between MMR, autism and inflammatory bowel disease (see 'Resources & Information' section: Medical Research on MMR autism and bowel disease, and other safety issues).
The safety of the vaccines was a concern for some parents. A few were worried about the information available on the long-term effects of the MMR vaccine. One mother who had these concerns had found it reassuring to learn that the same MMR vaccine used in the UK had been used in the USA since the early 1970s, and of the millions of children given MMR, accounts of reported adverse reactions was rare. (Also see Question and Answer below.)
A few of these parents had concerns about the ingredients of the vaccines and that live vaccines were given which the occasional parent personally believed were too much for a child's body to cope with. There has been no scientific evidence to suggest this is the case. The mumps, measles and rubella vaccines contain strains of the virus that has been weakened (attenuated) so that it will stimulate an immune response to natural measles, mumps and rubella viruses but will only produce very mild symptoms of these diseases, if any at all. (See Question 30 in Q&A' section).
Wakefield A J et al. Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. Lancet 1998; 351: 637-41.
Question: What research has been done on the long-term side effects of the immunisations?
There has been a lot of research on the long-term side effects of MMR and whooping cough vaccines. The research has been done in two main ways: firstly, there have been studies which follow children throughout their childhood, to see what health problems, if any, occur and to compare those who were immunised than those who were not. These cohort studies (to use the technical term) have been easiest to do in Scandinavian countries where the medical records are kept in a carefully co-ordinated way. As Scandinavian countries started using MMR vaccine before the UK, their studies of vaccine safety have been very useful. These studies are summarised in the section on Medical Research on MMR. The second method is used when a health problem, for example autism or bowel disease, is suspected as being caused by a vaccine. What is done is to study a group of children with the health problem (“cases”) and compare their immunisation records with children who do not have the condition (“controls”). These “case-control” studies can give answers relatively quickly, and are particularly useful when the health problem in question is relatively uncommon. Consistency of results across several studies gives reassurance of reliability. However, research findings are always limited to the questions that are asked, so that conditions that have not been foreseen as side effects of vaccines may not be identified.
Monitoring for vaccine effectiveness and safety is an integral part of the immunisation programme to measure the impact of the uptake of immunisation on the incidence of disease and to pick up any rare adverse events which may not have been observed in clinical trials. It was this process that picked up the small risk of aseptic meningitis in MMR vaccines manufactured using the Urabe strain of mumps vaccine virus, which led to the immediate withdrawal of two brands of MMR in 1992.
The World Health Organisation monitors adverse events associated with immunisation, as described on www.who.int/immunization_safety/aefi/en/
Last reviewed June 2011.
