Autism is a developmental disorder that affects social interaction and communication skills. It occurs in children before the age of 3. It is not certain how big of a role genetics play in autism, but it is believed to play a large role. For many years vaccines, such as the measles vaccine, have thought to play a role in causing autism, but a new report seems to disprove this.
The measles-mumps-rubella (MMR) vaccine is an immunization that is usually given to children who are about a year old. A second shot is given several years later when the child is around 4 years old. Around 3% of people do not become immune to measles after the first shot and so the second shot is aimed at create immunity in these people. The second dose was not introduced until the 1990's, but the MMR vaccine was first developed in the 1960's.
Today it is used across the world and today less than 1% of people who are under 30 contract measles. The decline in those who contract measles has greatly reduced the number of cases. It is estimated that in the first 20 years of the vaccines use, over 21 million American deaths were prevented.
In 2005 there were only 66 cases of reported measles in the United States. Over half of these cases were traced back to a single unvaccinated person who visited Romania. He returned to America and infected 34 people who were mostly children and almost all were unvaccinated.
In 1998 a paper written in part by Andrew Wakefield cited a link between the MMR vaccine and autism. The study found a link between autism and gastrointestinal problems that was aggravated by the MMR vaccine. He suggested that the vaccination should be split up into 3 separate doses, but this has not been shown to reduce the risks associated with the disease. After his study, there was a reported declination in vaccinations.
Recently, a study conducted by Columbia University, the United States Center for Disease Control, Massachusetts General Hospital, and Ireland's Trinity College has concluded that there is no link between autism and the MMR vaccine. The scientists took tissue samples from children who have gastrointestinal problems and autism. These tissue samples were compared to samples from children with similar gastrointestinal problems who do not have autism.
One of the theories presented by Wakefield's paper was that the measles virus would grow in the intestines and spread through the body. Using the same process as Wakefield, but with advanced technology, the scientist did not see evidence of this in the children. Of the 25 children with autism, only one shown signs of the measles virus and of the 13 children without autism, only one shown signs of measles.
These findings appear to disprove Wakefield's original study, but some are unconvinced and feel that the study only addresses one theory and does not rule out that vaccines could play a part in autism.