Vaccinations have had a rumored connected to autism for nearly 25 years, but a new analysis of 67 research studies shows there is no evidence to scientifically back the claims up and, in addition, shows adverse side effects are very rare. The study, which was commissioned by the federal government, was published Tuesday in the journal of Pediatrics.

“Concerns about vaccine safety have led some parents to decline recommended vaccination of their children, leading to the resurgence of diseases,” the study’s co-author, Dr. Courtney Gidengil, pediatrician at Rand and Boston Children’s Hospital, and colleagues wrote in their report. "This report should give parents some reassurance.”

Parents can rest easy knowing that vaccines shouldn’t be their primary concern, but instead other possible theories on why autism diagnoses are on the rise should be looked at. Currently, there is no pinpointed cause for autism, but it’s generally accepted in the medical community that certain culprits cause abnormalities in the brain structure or function in early developmental stages in children.

Possible Causes of Autism:

  1. Environmental exposures such as prenatal pesticide exposure. There is a 60 percent increased risk for women in their third trimester who live close to farms or open fields where pesticides are readily used, according to a recent study.
  2. Parental birth-giving age of mothers who are 40 years or older have a 50 percent greater risk of having a child with autism compared to women in their 20s, according to the National Autism Association.
  3. Pharmaceutical exposures to babies who are still in the womb are at a higher risk for autism, including SSRIs, valproic acid, and thalidomide.

Where did the rumored connections between vaccines and autism begin? A former British surgeon and medical researcher, Andrew Wakefield, and 12 others authored a scientific study in 1998 that claimed to have found a connection between the measles, mumps, and rubella (MMR) vaccine and autism. However, after a decade-long series of studies, researchers consistently found no connection and in 2010 retracted the study for the paper’s scientific limitations, such as the small group of test subjects.

“Who perpetrated this fraud? There is no doubt that it was Wakefield. Is it possible that he was wrong, but not dishonest: that he was so incompetent that he was unable to fairly describe the project, or to report even one of the 12 children’s cases accurately? No. A great deal of thought and effort must have gone into drafting the paper to achieve the results he wanted,” wrote British Medical Journal Editor-in-Chief Fiona Godlee, Deputy Editor Jane Smith, and Associate Editor Harvey Marcovitch.

The ethics committee ruled that he had failed his responsibilities as a consultant and was dishonest and irresponsible to approve and edit the final research paper, which was published in The Lancet. He was taken off the Medical Register in May 2010 and was barred from practicing medicine in the UK.

"There is a lot of misinformation out there about vaccines," said co-author Margaret Maglione, also a researcher with Rand. "With the rise of the Internet and the decline of print journalism, anyone can put anything on the Internet."

Since then, there has been a steady decline in vaccinations. Parents, who originally heard of the study, oftentimes didn’t hear of the retraction and falsehoods that were discovered, and as a result, nearly one in four children do not receive all of their recommended vaccinations. According to the Centers for Disease Control and Prevention, vaccines given to infants and young children in the past 20 years will prevent 322 million illnesses, 21 million hospitalizations, and 732,000 deaths throughout their lifetime.

Yet, at least 539 people in the United States have been infected with measles this year alone.

"The most dangerous aspect of giving your child vaccines is driving to the office to get them," said pediatrician Paul Offit, chief of infectious disease at Children's Hospital of Philadelphia and a developer of the RotaTeq vaccine.

Source: Gidengil C, Maglione MA, Das L, et al. Safety of Vaccines Used for Routine Immunization of US Children: A Systematic Review. Pediatrics. 2014.