What is the story?
The controversy over MMR has been reignited following claims in the UK media that fresh evidence to support a link between autism and the triple vaccine has been uncovered.
The papers reported that US researchers had found the measles virus of the strain used in the triple-jab in the guts of autistic children.
The media has said the study will spark concerns over MMR because it seems to support theories of a causal link between the triple jab and the painful gut disorders suffered by some autistic children.
The findings appear to back-up the work of gastroenterologist Dr Andrew Wakefield, whose original study, which purported to find a possible link between MMR and autism, was dismissed as 'bad science' by health officials.
Dr Wakefield caused a media storm in 1998 when he claimed to have discovered a new bowel disease: 'autism enterocolitis'.
At the time, Dr Wakefield said that although he had not proved a link between MMR and autism, there was cause for concern.
He suggested the government should offer the option of single vaccines until more research had been done.
The paper, which appeared in the Lancet, caused widespread concern and caused vaccine uptake to plummet.
What is the research?
The study, led by Arthur Krigsman, clinical assistant professor in the department of paediatrics at the New York University School of Medicine, involved 275 patients diagnosed with autism who were seeking help for serious and unexplained digestive problems.
The children were examined and their medical histories, vaccination records, histopathology reports and ileocolonoscopic biopsy tissue were evaluated.
Serious intestinal inflammation was found in some of the autistic children, and biopsies of gut tissue were performed on 82 of them.
Evidence of the measles virus was found in 70 of these. This has also been confirmed in 14 cases by DNA tests.
These results mirror Dr Wakefield's 1998 findings, and those of pathologist Professor John O'Leary from Trinity College, Dublin in 2002.
The results of the study - presented at the International Meeting for Autism Research in Montreal, Canada last week - have yet to be accepted for publication by a scientific journal or subjected to peer review.
What do the researchers say?
Dr Stephen Walker, assistant professor at the Wake Forest University School of Medicine, North Carolina - one of the study researchers who analysed the gut samples - described the research as 'very exciting.'
'Wakefield's study was criticised because it lacked replication. Our goal is to see if the finding was real. Preliminary results show that it was,' he said.
'This research proves that in the gastrointestinal tract of a number of children who have been diagnosed with regressive autism, there is evidence of the measles virus.'
He added that the small amount of data to have been analysed so far indicated that the measles found in the guts of autistic children all matched the vaccine strain of the virus: 'Of the handful of results we have so far, all are vaccine strain and none are wild measles.'
What do other experts say?
Dr Wakefield, who caused the original MMR outcry, has welcomed the study.
'The DoH was able to discredit our research by saying no one else had found similar results to ours.
'In the light of these results which are strikingly similar to ours, the government and its regulators are obliged to act,' he said.
But the DoH and BMA have reiterated their claims that MMR is safe. A recent analysis of 31 MMR studies by the Cochrane Library showed no grounds for claims of serious harm.
Dr George Kassianos, RCGP immunisation spokesman, said the results of this study were not enough to change policy.
'This has not been published and is experimental research. All drugs can cause complications but MMR is a very safe vaccine,' he said.
International Meeting for Autism Research
Live links at GPonline.com
- US researchers have found evidence of measles in the guts of autistic children with a bowel disorder.
- The study has not yet been accepted for publication by any journal.
- The risk of serious complications or dying from measles is many times higher than the risk of suffering an adverse reaction to MMR.
- A Cochrane review of studies on MMR has concluded that it is safe.
WHAT THE PAPERS SAID
"US study supports claims of MMR link to autism"
The Daily Telegraph
"US scientists back autism link to MMR"
"Scientists fear MMR link to autism"