Do childhood vaccines contribute to ASDs?
Childhood vaccines, including the measles/mumps/rubella (MMR) vaccine, do not cause ASDs. Many studies have shown no link between the MMR vaccine and ASDs. In fact, the controversial 1998 study that set off concerns about a possible link between the MMR vaccine and ASDs was recently retracted by the medical journal Lancet that originally published it (13). Some parents of children with autism suspected that the MMR vaccine, given around 12 to 15 months of age, contributed to ASDs because their children began to display symptoms of ASDs around the time they were vaccinated. Most likely, this is the age when symptoms of the disorder commonly begin, even if a child is not vaccinated. Another reason that childhood vaccines were suspected of playing a role in ASDs is that, until recently, they contained a small amount of a preservative called thimerosal. Thimerosal contains mercury. While higher doses of certain forms of mercury may affect brain development, studies suggest that thimerosal
