Fact: No Link Between Vaccines and Autism

By Arthur Caplan, PhD

What must it be like to spend a huge amount of time every waking day trying to change public health practice, only to find out that you were wrong?

That is precisely what has happened to the proponents of the theory that mercury in vaccines—contained in the preservative thimerosal, which once was used (and is used no longer) in vaccines—is responsible for a nearly 20-year explosion in autism and other neurological disorders among American children.

This urban legend has had very real and terrible consequences. It has led, and continues to lead, many parents to avoid getting their kids and themselves vaccinated against life-threatening diseases. The failure to vaccinate has caused many preventable deaths and avoidable hospitalizations from measles, whooping cough, diphtheria, flu, hepatitis, and meningitis. And the fear of vaccines puts each one of us at risk that we, our children, or our grandchildren will become part of a deadly outbreak triggered by someone whose parents avoided getting their child vaccinated for fear of autism.

Recent research on many fronts in medicine and science has nailed the coffin shut on the mercury-in-vaccines-causes-autism hypothesis. The connection is just not there. Perhaps the key fact, which has garnered little attention, is that thimerosal has been removed from vaccines in this and other countries for many years, with no obvious impact on the incidence of autism. The most recent data point toward a correlation with nothing at all to do with vaccines: the increasing age at which people (particularly men) have children seems to be associated with an increase in autism and other neurological problems.

Still, some of the most fervent anti-vaccine critics cannot let go. They continue to tell devastated parents of children with autism that vaccines are to blame. Others are still out on the lecture circuit peddling books and articles that bash vaccines and invoke mercury as a problem. Still, others pepper the Internet with the false message that vaccines and autism do go hand in hand, it is just that the government, the pharmaceutical companies, organized medicine, or all of them, are keeping the truth from us all.

Less than two years ago, Robert Kennedy Jr. published an article in Salon.com alleging that the government knew of and covered up the autism-vaccines connection.

Thimerosal was, Kennedy told large audiences and many media reporters, to blame.

Kennedy was hardly alone in fingering vaccines as the cause of the epidemic of autism affecting American children. David Kirby’s 2005 best-selling book, Evidence of Harm, and many other articles, newsletters, and advocacy blogs fanned the flames. Some continue to do so.

Proponents of the thimerosal/mercury-causes-autism theory have had a powerful impact on public opinion. When one of my students recently conducted a pilot study of attitudes about the new cervical cancer vaccine, fears about autism were prominent among the reasons many respondents gave for being wary of the vaccine. Friends of mine continue to tell me of parents in Lafayette Hill, Voorhees, Greenville, and Downingtown who won’t have their children vaccinated because of the risk of autism. States continue to allow parents to opt out of vaccines on “philosophical” grounds, perhaps the only arena in American public life where “secular philosophy” is given legal standing in public policy. And even some young healthcare workers report that they don’t get important vaccines that would protect them, their families, and their vulnerable patients against death because of worries about autism and vaccines.

Science and medicine have not bought the thimerosal/mercury-autism link. For years the Centers for Disease Control and Prevention, the American Academy of Pediatrics, the Children’s Hospital of Philadelphia’s Vaccine Education Center, the National Academy of Sciences, the Food and Drug Administration, and countless other prestigious organizations and scientists have said the data do not support mercury in vaccines as the cause of autism.

Now, with the mercury long out of vaccines, what is there left to say? Why won’t the slandering of vaccines as the cause of autism stop?

There has always been a great deal of antipathy toward vaccines, in part because vaccines do have a tiny chance of causing death or other serious side effects. Parents who have been through that hell have a hard time hearing or sending any other message other than “vaccines are bad.” And those who made careers out of peddling the vaccine-autism link—in the face of a lack of evidence—have really been motivated by a distrust of medicine, science, government, and experts, a distrust that has little to do with scientific studies or expert opinions. Even government officials have never really cared enough about public health to do much to counteract the incredible damage the autism vaccine proponents have done. That is not acceptable.

Our nation is spending a fortune on plans to cope with the prospect of a bioterror attack. State, city, and federal agencies are trying to figure out a plan if avian flu mutates into a form in which it can start killing people. Hospital officials are worrying about how to cut back on preventable deaths in our hospitals and nursing homes. Those in charge of keeping disease transmission in hospitals, schools, and public spaces to a minimum are fretting over what steps to take. The answer to every one of these challenges involves vaccines.

This nation’s future, its national security, the safety of its healthcare institutions, and the safety of its citizens depend upon vaccination. It is way past time that this message got heard by parents, teachers, nurses, doctors, hospital administrators, the media, and politicians. If there has been a more harmful urban legend circulating in our society than the vaccine-autism link, it is hard to know what it might be. At a time when vaccines may be our last best hope in facing some of the greatest challenges we and our children face, this legend needs to be put to rest. Vaccination, not vaccine-bashing, is what this nation needs.

Disclaimer: Immunize.org and VaccineInformation.org publish personal testimonies to make them available for our readers’ review. Please note that information in the testimonies may be outdated and may not reflect the current immunization schedule or recommendations. (Published: 2/27/2007)