Wednesday, February 07, 2007

Scientists Raise Voices Against Autism Parents' Vaccinophobia

A series of recent articles shows that scientists and public health advocates are finding their voice in advocating that all children get vaccinated against contagious diseases in spite of the fears of some parents that the shots are dangerous and could cause autism. Not all of the articles mention the fear wrought by one British scientist's theory published in 1998, and later disputed, that the mercury-containing preservative thimerosal in the some vaccines suggested a link between the vaccine and autism, but this "Wakefield study" is a part of the subtext.

"Fact: no link of vaccine, autism" is the headline to an op-ed in The Philadelphia Inquirer this week by Arthur Caplan, professor of bioethics at the University of Pennsylvania, and co-director of the Ethics and Vaccines Project there. Caplan calls the autism-vaccine theory a myth and writes:

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 fear of vaccines puts each one of us at risk that we, our children or 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.

You can read Caplan's article here. It appeared Feb. 6, just two days after The New York Times Book Review assessed the new book "Vaccine: The Controversial Story of Medicine's Greatest Lifesaver," by Arthur Allen. In this review, David Oshinsky, the author of the Pulitzer Prize-winning history work "Polio: An American Story," says that Allen has written a "splendid book" that aptly captures the risk-reward calculus that has always been part of the administration of vaccines since Edward Jenner successfully immunized a child against smallpox in 1796 England.

Allen's book recounts the religious, economic and other arguments against the smallpox vaccine (Napoleon loved it for his troops), the book reviewer says; current anti-vaccination sentiments have their roots in "the general fallout from catastrophes like Watergate and Vietnam, which undermined institutional authority across the board. ... The public's portrait of a medical researcher had turned from the selfless and independent [Jonas] Salk working on behalf of children to that of a lab-coated lackey from a drug giant conspiring to hide the dangers of products that are slickly marketed and wildly overpriced." The reviewer concludes:

To a large extent, says Allen, this antivaccination impulse is fueled by an ignorance of the past. Vaccines have done their job so well that most parents today are blissfully unaware of the diseases their children are being inoculated against. The end result is a culture that has become increasingly risk-averse regarding vaccination because people have greater trouble grasping the reward.

The problem appears to be growing. As more children go unvaccinated in the United States, there has been a rise in vaccine-preventable diseases. Meanwhile, fewer pharmaceutical companies are now producing vaccines, citing the high cost of testing, diminishing markets and a fear of litigation. For Allen, a reversal of these trends will require something long overdue: a frank national discussion about the risks and benefits of vaccination. His splendid book is a smart place to begin.

Autism is not mentioned in the review of this book, but we know it's on the author's mind. Last month, Arthur Allen penned one of several stories that picked up a thread in the book "Unstrange Minds," by anthropologist Roy Richard Grinker, to argue against the idea of an autism epidemic. You can read more about that issue here.

Scientists are doing more than writing histories like Allen and citing studies to argue in favor of the public health benefits of vaccines like Caplan. A team of researchers from the Stanford University Medical School just published a study in the February issue of Nature Reviews Neuroscience on the way the media covered news of scientific research and discoveries about autism. The researchers said they found a disconnect, as Stanford reports on its website:

While 41 percent of research funding and published scientific papers on autism dealt with brain and behavior research, only 11 percent of newspaper stories in the United States, United Kingdom and Canada dealt with those issues. Instead, 48 percent of the media coverage dealt with environmental causes of autism, particularly the childhood MMR vaccine for measles, mumps and rubella that was once linked with autism in a widely refuted study. Only 13 percent of published research was about environmental triggers of autism.
You can read an abstract of the study, "Interacting and paradoxical forces in neuroscience and society," by Judy Illes, Joachim Hallmayer and Jennifer Singh here, and the Stanford press release here.

The researchers suggest is that it's difficult to get the message out when the media doesn't prioritize coverage of issues the same way that scientists do. So it's incumbent on people like Caplan and Allen to bang their drums of scientific and public health advocacy. Illes, Hallmayer and Singh might say that they can't count on the media to do it for them.

(One interesting aside about the Stanford paper: it notes that media coverage about the 1998 paper by Wakefield eventually led to studies that refuted his findings and cited the safety of vaccines. And as Caplan notes in his newspaper column, it also led to the removal of thimerosal from vaccines. If it were not for the media coverage of the autism-vaccine controversy, one could ask, would these things have occurred? Would the drop in vaccinations be even more precipitous?)

Still, even with all the scientific research surrounding this issue, it can be difficult to take one's child to the doctor's office for a shot. Kristina Chew, who is a PhD and blogs about her life as the mother of an autistic son, wrote about this difficulty in her blog Autism Vox on Feb. 6:

Vaccine” and “autism” had become for me—have become in the public psyche—not merely linked. These two words, which have nothing intrinsically to do with each other, have become equated, and because of coincidence, of a correlation that seems to contain a clue to causation: An 18-month-old child receives her or his immunizations. An 18-month-old child is noticed to not be playing in varied ways, or interacting, or speaking. The parents know they have “done everything” to ensure their child’s health and development, have followed the advice of the pediatrician exactingly, and then some, so it must be some external agent, some mysterious force, that has caused this terrible change in a child.

I think, that is, it is possible to understand why so many parents believe in a vaccine-autism link. What I am trying still to understand, is how to dispute such a link; as Professor Caplan’s op-ed suggests, appeals to the evidence of science have yet to be effective.

So earlier in her son's life, she demurred from having him vaccinated. Later, when it came time recently to enroll her son in a new school, she took him for his vaccine shots.


Anonymous said...

Yes, exactly! You summed it up perfectly, Michael -- "...even with all the scientific research surrounding this issue, it can be difficult to take one's child to the doctor's office for a shot." For me, the mere possibility that any of the "trace amounts" of thimerosal that remain in some legally mandated childhood vaccines could be a poison of sorts coursing through my son's veins is enough to send me combing the Internet, frantically calling pharmacies and spending hundreds of dollars for mercury-free alternatives.

Anonymous said...

I have two son on the spectrum.My older one is 9 year old.When my younger son got vaccine I made sure that he gets Thimerosol free vaccines.My 2nd son still devloped autism.But one thing noteworthy was that he devloped autism right after he got MMR shot which they gave him at 12 months.So in my opinion vaccine component other than thimerosal are at work.