The misconception that childhood vaccines cause autism often stems from concerns about mercury (thimerosal) content, which was used in some vaccines to preserve the viability of viruses and bacteria. Many families with autistic children typically notice symptoms around 18 months of age, a period that coincides with the administration of routine triple combination vaccines. However, reports published by the World Health Organization (WHO) clearly state that ethylmercury (thimerosal) has a half-life of less than one week in the body and has not been shown to cause chronic diseases.