Debate on autism link to vaccines fired up again

In a relatively unusual event, federal health officials called a news conference this week in an attempt to affirm the safety of vaccines.

This came among the growing concern of some parents who allege that vaccines can cause autism.

A rally by autism activists is planned this week in front of the U.S. Capitol on to emphasize their belief that the government has concealed evidence linking autism to a mercury-based product once used in vaccines.

The activists will also demand more research into what they consider is the growing problem of autism.

Dr. Julie Gerberding, director of the U.S. Centers for Disease Control and Prevention (CDC) , said at the news conference, that there has been renewed interest in the issue of vaccine safety, particularly on whether the preservative thimerosal, may be linked to the occurrence of autism in children.

Unfortunately, autism is often diagnosed between the ages of about 18 months and four years, which is about the time that toddlers and young children are getting their vaccinations.

To date, no reports, and that includes a review of all the studies from the independent Institute of Medicine, have found evidence that vaccines cause autism.

Some groups of parents however allege a cover-up, and have resisted vaccinating their children.

This has led to outbreaks of diseases such as measles and whooping cough in Britain, the Netherlands and elsewhere.

These parents believe there is evidence, that at least some children, are sensitive to mercury, including the mercury in thimerosal.

In the United States Thimerosal is no longer used in childhood vaccines.

At the news conference CDC officials, as well as representatives of the National Institutes of Health, American Medical Association, American Academy of Pediatrics, and the Food and Drug Administration, made it clear they believed some of the groups were relying on incomplete information.

Dr Gerberding quoted one report that said as many as one in 166 U.S. children have autism, and said more studies were needed to get a "better and more reliable handle" on how many cases there are, but several recent studies have questioned the contention that autism rates have gone up in recent decades.

Said Dr. Eileen Ouellette, president-elect of American Academy of Pediatrics, says though they want to discover the causes of autism as well as how to prevent it and treat it, the evidence does not point to vaccines as one of those causes.

Just as health officials were hoping the debate had finally been settled, it was ignited again with a book by former journalist David Kirby which alleges a potential link.

A television interview in which Robert Kennedy Jr., nephew of slain president John F. Kennedy, alleged a conspiracy, has also added fuel to the debate.

Kirby plans to speak at the rally.

The timing of the news conference has also raised suspicions among the activists. The National Autism Association has said in an e-mail to supporters and journalists, that they believe the CDC press conference is an attempt to head off publicity from the rally that would direct attention to the role of thimerosal and vaccines in autism.

Gerberding has acknowledged the mistrust, and understands that parents want answers, but says care needs to be taken so decisions are not based on unproven hypotheses and fear.