Why does she take issue? Answer: mercury, used as a preservative in some vaccines (chicken pox, for example) and linked to some instances of autism, was REMOVED from all vaccines in or before 2001. McCarthy insists that the MMR vaccination series her son was given AFTER his birth in 2002 caused his autism. She even wrote a book about it--"Louder Than Words: A Mother's Journey in Healing Autism."
Yes, mercury (or rather thimerosal, the mercury compound in question) has been known to cause various health issues, perhaps including autism. However, that chemical is long gone from vaccines, so today's parents don't have to worry about that. There are several more discrepancies (Brown opines that the Ph.D. from "University of Google" contributed to McCarthy's, shall we say, incomplete knowledge about some facets of autism) in the book.
Brown, a longtime Texas pediatrician, understandably terms this hysteria "New McCarthyism," i.e. "Who cares about 100 years of scientific research? Vaccines are evil, because the Internet says they are." I'll end with Brown's 1994 pre-chicken-pox-vaccine, tear-jerking anecdote...
...Cradled in the arms of her parents, a seven-year-old girl was brought to the emergency room at Children's Hospital Boston. The girl had come down with chickenpox a few days earlier -- she had a fever and hundreds of itchy skin lesions. That night, she had taken a turn for the worse. Her fever shot up to 106 and she became confused and lethargic. She was unresponsive and limp in her mother's arms.
The ER doctors suspected that her open sores allowed Strep bacteria to get under her skin and rage through her bloodstream. Now she was in "multiple system organ failure" -- every square inch of her body was shutting down all at once. IVs were placed into her veins to start fluids, antibiotics and medications to stabilize her heart and blood pressure. She was placed on a ventilator machine to breathe. Then she was brought to the Intensive Care Unit.
By the time I met my patient, she had tubes coming out of every opening and weeping skin lesions all over her body. I was used to blood and gore, but it was hard to look at her and not cry. Imagine how her parents felt when they saw their once-beautiful little girl in this grotesque state, struggling to survive.
My attending physician told me to grab dinner. This child would need me for the rest of the night. I returned to the ICU to find that my patient had gone into cardiac arrest and died. I watched, helplessly, as the nurses placed the little girl into a body bag.
Fast forward five months: The first chickenpox vaccine was approved. That day, I vowed never to let a child on my watch suffer from a disease that was preventable by vaccination.