It’s back to school time, which means physical examinations and immunizations for many school-aged children. Of course, most children dread the idea of getting vaccinated so I’m sure that doesn’t make them excited about going back to school.
In the past decade, the children aren’t the only ones protesting vaccinations. Although the scientific data has been limited, several small and highly controversial studies have linked vaccines to autism.
The autism spectrum disorders are a range of complex neurodevelopment disorders, characterized by social impairments, communication difficulties, and restricted, repetitive, and stereotyped patterns of behavior. The symptoms of autism spectrum disorders vary significantly in character and severity among individuals. Approximately 1 out of every 150 children has and it occurs in all ethnic and socioeconomic groups. Boys are up to four times more likely to have an autism spectrum disorder than girls.
Despite the fact that the Centers for Disease Control and Prevention, the World Health Organization, the Institute of Medicine and the American Academy of Pediatrics all agree that there is no evidence to support a relationship between autism and vaccines, some people strongly believe that there is a link.
Actress Jenny McCarthy, whose son has autism, has stated that she believes that a vaccination caused her son’s autism. She is not alone in this belief.
Because there is no known cause of autism and the scientific data is often difficult to understand, parents and families are left searching for answers. Without concrete answers, there is a desire to blame something and vaccines are easy targets.
There are two issues related to vaccines and autism. In 1998, a British physician and research published a report linking 12 children with autism to the measles, mumps, and rubella (MMR) vaccine. In the report, all 12 children were reported to have developed autistic symptoms as well as digestive symptoms shortly after their first dose of the MMR vaccine. The researchers suggested that the vaccine might trigger the development of autism.
Since this study was published, at least 14 studies, which include millions of children, have consistently found no difference in autism rates between children who received the MMR vaccine and those who didn’t. Additionally, it was found that the primary author of the initial report was receiving large amounts of money from people who would sue the makers of the vaccine and that the researcher likely falsified the records to show a link between the vaccine and autism.
In February 2010, Lancet, the prominent medical journal that published the first report, issued a retraction citing ethical issues.
The second issue involves vaccines containing the chemical preservative thimerosal, which contains a form of mercury. Mercury poisoning can cause brain damage and some of the symptoms are similar to those in autism. Still there is no proof that vaccines containing thimerosal have caused autism.
In 1998, there were a number of different vaccines that included thimerosal so there was concern that some children could receive doses of mercury that exceeded the limit considered safe. In 1999, the U.S. Public Health Service and the American Academy of Pediatrics recommended that vaccine manufacturers either reduce or remove thimerosal from vaccines. Since 2001, all routine childhood vaccines have been available thimerosal-free.
Even though there is no conclusive evidence to support a link between vaccines and autism, some parents remain concerned about this possibility.
Because autism is often diagnosed in early childhood, the time of the diagnosis around the time that many children are receiving vaccinations. Of course, this does not mean that they are related.
Currently, the benefits of childhood vaccines outweigh the risks. We know that vaccinations can prevent serious and life-threatening illnesses including polio, measles, and hepatitis; while there is no consistent scientific data to support a causal relationship between vaccines and autism.
To learn more about vaccines and autism, visit www.cdc.gov/vaccinesafety/Concerns/Autism/Index.html
