SAN FRANCISCO, Nov. 17 (UPI) -- While many consider the case against vaccines and autism closed, there is some movement afoot among public-health agencies and policymakers who are shifting away from an automatic dismissal of environmental factors. They say they also are paying more attention to parental feedback.
At the heart of the debate is a mercury preservative called thimerosal that was used in several childhood vaccinations through the early part of this decade -- and remains in some flu and booster shots. Critics are also concerned about the possible impact of certain vaccines, such as the measles-mumps-rubella shot, and the cumulative load of immunizations in young children.
"(T)he preponderance of evidence consistently does not reveal an association between thimerosal and autism," Dr. Julie Gerberding, director of the Centers for Disease Control and Prevention in Atlanta, said at a news briefing on vaccines and health in February.
"But I can't sit here today and tell you with 100 percent certainty that there is absolutely never going to be any association of thimerosal and autism in one or more children," she added.
"When you're dealing with a problem as complicated as this one and as important to so many children and so many families across the United States, we have a responsibility to be open to any and all hypotheses."
Among studies exploring thimerosal's effects, a six-year survey launched in September 2001 by the National Institute of Environmental Health Sciences is following 2,000 children between ages 2 and 5.
The aim is to determine how genes, environment and their interplay fit into the mix that gives rise to autism and other neurodevelopmental disorders.
In addition, in a Feb. 22, 2006, letter signed by Sen. Joseph Lieberman, D-Conn., and seven fellow members of Congress contending the CDC has not adequately explored the issue, the agency was asked to conduct a new investigation into a potential vaccine-autism link.
On a federal Web site, government officials assure of their open-mindedness.
"CDC continues to support research related to autism, including studies designed to examine the possible causal association between autism and other possible environmental causes, including thimerosal-containing vaccines," states an open letter signed by Dr. Stephen Cochi, acting director of the agency's National Immunization Program.
That's all many of the critics are after -- to keep the door ajar to all possibilities until the real causes can stand out and be counted.
"It is critical that there be an investment of time and money to find out whether the use of multiple vaccines in early childhood is doing more than just eliminating or controlling infectious disease," said consumer advocate Barbara Loe Fisher, co-founder and president of the National Vaccine Information Center.
"We must find out if preventing all infection in early life with the use of multiple vaccines is setting up a significant number of children for the development of chronic disease," she said. "What is at stake is nothing less than the biological integrity of the human race."
Many specialists, however, think the vaccine question has gotten more than its scientific due and that the time has come to take advice included in an Institute of Medicine report and move on to "the most promising areas."
"Would it not make more sense to invest in studying and implementing treatments like behavior therapy that might have a big chance of helping children rather than in an elusive pursuit of an environmental suspect against which there's very little scientific evidence?" said Dr. Daniel Geschwind, professor of neurology and psychiatry and director of the Neurogenetics Program at the Center for Autism Research and Treatment at the University of California, Los Angeles, School of Medicine, and author of "Microarrays for the Neurosciences" (MIT Press, 2002).
"Would it not be more productive to focus more attention on regressive autism and possible environmental causes other than vaccines, which already have been cleared by substantial amounts of scientific testing?" he added. "The focus on vaccines may be taking researchers' attention away from other environmental factors that might in fact prove to be involved in the disorder."
New research avenues are being paved with the advent of novel disciplines like molecular genetics and biological measures of stress, a 10-year review of autism-related literature pointed out.
Cutting-edge strategies and razor-sharp instruments are starting to clear multiple paths toward autism's core, the authors noted.
In a departure from past protocols, the present-day undertakings increasingly find parents casting off their traditional role as spectators to play a dramatically different part. Moms and dads typically found waiting in the wings are taking center stage, producing the impetus for a push for progress and providing direction for future research.
"This is an area that really takes a village -- this is not going to be done by one sector, not going to be done by one laboratory or one part of the service community," said Dr. Thomas Insel, director of the National Institute of Mental Health.
"I've often said, and I continue to believe this, that parents in this case are some of the best experts, and we've learned a tremendous amount from them about what needs to be done and what can be done better, and it certainly involves the advocacy community, which has become in this case a very important partner in the future research effort and the current way of setting research priorities."
As that collaborative effort gets under way, the only certainty is that all the parties have their work cut out for them.
(Note: In this multi-part installment, based on dozens of reports, conferences and interviews, Ped Med is keeping an eye on autism, taking a backward glance at its history and surrounding controversies, facing facts revealed by research and looking forward to treatment enhancements and expansions. Wasowicz is the author of the forthcoming book, "Suffer the Child: How the American Healthcare System Is Failing Our Future," to be published by Capital Books.)
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