In the past, some researchers worried that

 

 

 

 

 

vaccination
A vaccination is an injection a doctor can give you to protect you from getting an infectious illness (an illness that spreads between people).

 

 

 

 

 

vaccination with the MMR vaccine might be linked to your child getting autism. But there isn't any good evidence of this.

Here is some more information about this vaccine and autism.

MMR stands for measles, mumps and rubella (German measles). These are

 

 

 

 

 

infection
You get an infection when viruses, bacteria, fungi or other tiny organisms get into your body. These bugs are so tiny that you can't see them without a microscope. For example, an infection in your airways causes the common cold. And an infection in your skin can cause rashes such as athlete's foot.

 

 

 

 

 

infections that can make your child very sick.

Usually, with the MMR vaccine, your child gets one shot when they are about 13 months old and another one when they are between 2 years and 4 years old.

The MMR vaccine protects your child from all three infections.

A study in 1998 raised questions about the MMR vaccine and autism.

 

 

 

 

 

Source:
Wakefield AJ, Murch SH, Anthony A, et al.
Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children.
Lancet. 1998; 351: 637-641.

 

 

 

 

 

¹ The researchers thought there might be a link between having the vaccine and getting a problem with your bowels. This bowel problem might cause a kind of autistic spectrum disorder. But in the end, the researchers said that their study didn't prove any such link.

This study was small, with only 12 children. And other researchers said it wasn't done well.

 

 

 

 

 

Source:
Wilson K, Mills E, Ross C, et al.
Association of autistic spectrum disorder and the measles, mumps, and rubella vaccine: a systematic review of current epidemiological evidence.
Archives of Pediatrics and Adolescent Medicine. 2003; 157: 628-634.

 

 

 

 

 

² But the study showed up in newspapers and on television. Then some parents decided not to give their children the MMR vaccine.

 

 

 

 

 

Source:
Drug and Therapeutics Bulletin.
MMR vaccine: how effective and how safe?
Drug and Therapeutics Bulletin. 2003; 41: 25-29.

 

 

 

 

 

³

It can be hard to prove beyond any doubt that a vaccine is safe. This is because millions of children get vaccines. And some of these children later get diseases. But this doesn't mean the vaccine caused the diseases.

To prove a link between the MMR vaccine and autism, we would need to do a type of study called a

 

 

 

 

 

randomized controlled trials
Randomized controlled trials are medical studies designed to test whether a treatment works. Patients are split into groups. One group is given the treatment being tested (for example, an antidepressant drug) while another group (called the comparison or control group) is given an alternative treatment. This could be a different type of drug or a dummy treatment (a placebo). Researchers then compare the effects of the different treatments.

 

 

 

 

 

randomized controlled trial. In this study, some children would get the vaccine and some wouldn't.

But this study would be hard to do, for several reasons. We know that vaccines help a lot in stopping infections. So it wouldn't be fair to keep some children from getting vaccines. Also, the study would have to go on for many years, to spot any problems that take time to show up.

Other types of studies can give us reliable evidence about the MMR vaccine and autism. Two important types are called

 

 

 

 

 

cohort study
A cohort study follows a group of people (a cohort) and records the different things that happen to them. For example, a cohort study could find out whether lung cancer is more common in people in the cohort who smoke. Prospective cohort studies (which begin at a certain time and then look at what happens to the people in the study) are more reliable than retrospective cohort studies (which look at groups of people after events have happened to them).

 

 

 

 

 

cohort studies and

 

 

 

 

 

case control studies
A case control study compares patients in a case group with patients in a control group. Only the case group receives the treatment or exposure that is being studied. Both groups are looked at during the study to see if there are any differences in what happens to them. Retrospective case control studies compare the exposures of patients who developed a certain disease (such as cancer) with those who did not. Case control studies are considered a weak form of clinical evidence.

 

 

 

 

 

case control studies.

There have now been many of both of these types of study on the MMR vaccine and autism. One summary of the research looked at 12 of the best of these studies. It found that there wasn't any evidence of a link between the MMR vaccine and autistic spectrum disorder.

 

 

 

 

 

Source:
Wilson K, Mills E, Ross C, et al.
Association of autistic spectrum disorder and the measles, mumps, and rubella vaccine: a systematic review of current epidemiological evidence.
Archives of Pediatrics and Adolescent Medicine. 2003; 157: 628-634.

 

 

 

 

 

²

A recent high-quality study looked at blood levels of measles virus or antibody in children with autism who'd had the MMR vaccine. The study found that the levels of measles virus or antibody in these children's blood was no higher than in children without autism. This shows that the MMR vaccine doesn't cause problems in the way some doctors thought it might.

 

 

 

 

 

Source:
Baird G, Pickles A, Simonoff, et al.
Measles vaccination and antibody response in autism spectrum disorders.
Archives of Disease in Childhood. 2008; 93: 832-837.

 

 

 

 

 

⁴ You can get single vaccines for measles, mumps and rubella. But there isn't any evidence that these are safer than the combined MMR vaccine. And they haven't been tested as much as the MMR.

 

 

 

 

 

Source:
Centers for Disease Control and Prevention.
Vaccine safety: measles, mumps and rubella (MMR) vaccine.
December 2008. Available at http://www.cdc.gov (accessed on 23 April 2009).

 

 

 

 

 

⁵

Also, the full course of single vaccines involves six injections, instead of two injections with MMR. This means more visits to your doctor and more pain for your child, which probably means some children don't get the full course. It also means your child could get one of these infections while waiting for the next single shot.

In the United States, experts recommend that children get the MMR vaccine instead of the single vaccines for measles, mumps and rubella.

 

 

 

 

 

Source:
Centers for Disease Control and Prevention.
Vaccine safety: measles, mumps and rubella (MMR) vaccine.
December 2008. Available at http://www.cdc.gov (accessed on 23 April 2009).

 

 

 

 

 

⁵

You can find out more about autism and the MMR vaccine on the website of the National Institute of Child Health and Human Development (http://www.nichd.nih.gov/).

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