Review refutes link between MMR vaccine and illness
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 Even though the paper has since been retracted by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.”
SOURCE: The Cochrane Library, October 19, 2005.