When we worry, we worry the most about our children. Everyone wants to keep them safe.
When politicians want us to fall in line, they always talk about saving the children. And our feelings about kids have created very intense emotions about vaccines. Some people say vaccines are dangerous. Robert F. Kennedy Jr. said that they have "poisoned an entire generation of American children."
Kennedy has added his voice to the chorus of angry parents who are convinced that mercury in vaccines causes harm to children.
"It's causing IQ loss, mental retardation, speech delay, language delay, ADD, hyperactivity," he said.
Barbara Loe Fisher, who heads the Vaccine Information Center, goes on television to alert parents about the dangers of vaccines.
On the "Today Show," she said, "We need to find out why so many of our highly vaccinated children are so sick."
The biggest worry today is autism. Before kids received so many vaccines, says Fisher, "you didn't see autistic children. Autism was so rare. Most people had never heard of it."
And the protestors blame the vaccines.
Dr Paul Offit is the chief of infectious diseases at Children's Hospital of Philadelphia. He's also in the vaccine business. He developed and patented the rotavirus vaccine.
"I think that it's perfectly reasonable to be skeptical about anything you put into your body, including vaccines," said Offit. "And vaccines do have side effects. But vaccines don't cause autism."
Offit can say that with confidence because the National Academy of Sciences recently reviewed the science. They concluded that 19 major studies, tracking thousands of kids, all show no link between vaccines and autism.
"The question has been raised, it's been answered," said Offit. "Vaccines don't cause autism."
Then why are so many kids being diagnosed with autism? Because kids we once said had other conditions are now being called autistic.
As researchers from the March of Dimes put it, "improvements in detection and changes in diagnosis account for the observed increase in autism." Their data on autism rates in California showed that the increase in autism diagnoses almost exactly matched a decline in cases of retardation: autism prevalence increased by 9.1 cases per 10,000 children, while mental retardation dropped by 9.3 per 10,000.
"People that we once called quirky or geeky or nerdy are now called autistic," said Offit. "Because when you give that label of say, autistic spectrum disorder, you allow that child then to qualify for services which otherwise they wouldn't be qualified to get."
Two decades ago, "20/20" did a report which said that the whooping cough vaccine may lead to permanent neurological disorder and Sudden Infant Death Syndrome (SIDS).
Personal injury lawyer Allen McDowell said vaccine makers were victimizing kids, and more than 20 years later, he still says the vaccine makers put money before safety.
"There's no dispute about that. They were making so much money off the old vaccine they didn't really have any incentive to improve it."
McDowell made money too. The lawyer won lots of lawsuits.
"I made -- a good chunk of money," he said.
The vaccine makers did revise the whooping cough vaccine and the new version was approved by the FDA in 1991.