Saturday, October 22, 2005

Autism Spectrum Disorder & more vaccine finding results

NEW YORK (Reuters Health) - An extensive review of studies examining outcomes after immunization with the measles-mumps-rubella (MMR) vaccine has turned up no credible evidence that the vaccine is associated with autism or Crohn's disease or other serious illnesses.
In 1998, a case series of 12 children was reported suggesting that the MMR vaccination triggered an autism-colitis syndrome. Even though the paper has since been retracted by most of the original authors, it prompted parents to refuse vaccination for their children.
As a result, new measles epidemics occurred in which some patients died, lead author Dr. Vittorio Demicheli, from Servizo Sovrazonale di Epidemiologia in Alessandria, Italy, told Reuters Health.
"In a country where almost everyone is vaccinated against measles, it would be a common finding for a number of cases of any disease to have vaccination as a common factor," he noted.
After a wide-ranging search of the literature, the investigators identified 31 studies published between 1966 and 2004 testing the effects of MMR. The researchers report their analysis in the current issue of The Cochrane Database of Systematic Reviews.
"What is convincing for us is the consistency across different settings, different populations, and different study designs," Demicheli said. "Not a single study found any" evidence of serious adverse effects of the MMR vaccine.
Although he believes no further research of this issue is warranted, the researcher recommends that the way that adverse events are collected should be standardized across countries, and that doctors should document the brand of the vaccine that they use, since there are several currently being distributed.
He emphasized that "public health authorities and decision makers need to (publish findings) only when they are reasonably sure of the reliability of their information and after a more serious process of peer review. It is very dangerous to alert people in the absence of sound evidence."