Now, the argument should be over. This study effectively puts the nail in the coffin to the now disproven theory that the MMR vaccine is associated with or causes autism. Period.
See my May blog on all the background to this controversy.
But now, Reuters is reporting that scientists who tried to replicate a study that once tied a measles vaccine with autism said on Wednesday they could not find any link and hope their study will encourage parents to vaccinate their children to combat a rash of measles outbreaks.
Parents’ refusals to have their children vaccinated against measles have contributed to the highest numbers of cases seen in the United States and parts of Europe in many years.
Measles kills about 250,000 people a year globally, mostly children in poor nations.
Public health officials have been stressing the safety of the combined measles-mumps-rubella, or MMR, shot and other childhood vaccines in the face of vocal groups who claim the immunizations may cause autism and other problems.
The U.S. Institute of Medicine has issued several definitive reports showing no connection between autism and any vaccinations.
This study took a new tack. It attempted to replicate 1998 research by a team led by Dr. Andrew Wakefield, then of Britain’s Royal Free Hospital, in the Lancet medical journal that suggested the vaccine was linked to autism and gastrointestinal problems.
Wakefield is undergoing disciplinary action for professional misconduct by Britain’s General Medical Council and 10 of his collaborators formally withdrew their original Lancet study. And Lancet formally retracted the Wakefield study. You can read more about this in an earlier blog of mine.
Scientists at Columbia University in New York and the U.S. Centers for Disease Control and Prevention in Atlanta looked for evidence of genetic material from the measles virus in intestinal tissue samples taken from 25 children with autism who also had GI problems. They compared these to samples from 13 children of similar ages who had GI problems but no autism.
The samples were analyzed in three laboratories that were not told which came from the children with autism. One of the labs had been involved in the original study suggesting a link between measles virus and autism.
“We found no difference in children who had GI complaints and no autism and children who had autism but no GI complaints,” Dr. Ian Lipkin of Columbia University told reporters in a telephone briefing.
The team also collected data about the children’s health and immunization histories from parents and physicians to see if vaccinations preceded either their autism or bowel trouble.
“We found no relationship between the timing of MMR vaccine and the onset of either GI complaints or autism,” Dr. Mady Hornig, also of Columbia, said in a statement.
But the study did find evidence that children with autism have persistent bowel troubles that should be addressed.
“No longer can mainstream medicine ignore parents’ claims of clinically significant GI distress,” said Rick Rollens, a parent and autism research advocate. Nevertheless, it does, for all intents and purposes settle the question of whether the MMR vaccine causes autism. That answer is now, and conclusively, “No!”
The CDC estimates that about one in every 150 children has autism or a related disorder such as Asperger’s syndrome — 560,000 people up to age 21 in the United States. And now we need to turn our sites on finding the cause or cause — but we need to look elsewhere.
The findings, reported in the journal Public Library of Science and were widely covered in the media. Here are just a few examples:
ABC World News reported that new research “offers the most powerful evidence yet that there is no link between autism and the MMR vaccine, given to millions of children to protect them against measles, mumps, and rubella,” according to a study published online in the journal PLoS ONE.
The Washington Post reports that these “findings contradict earlier research that had fueled fears of a possible link between childhood vaccinations and a steep increase in autism diagnoses.” Ten years ago, The Lancet “published a study by British researcher Andrew Wakefield of 12 children with autism and other behavioral problems that suggested the onset of their behavioral abnormalities was linked to receiving the MMR…vaccine.”
The Post notes that “the new study comes as the U.S. Court of Federal Claims in Washington is in the midst of evaluating evidence on whether children’s vaccines are implicated in causing autism. A special master is evaluating three different ki nds of claims — two of which specifically link the MMR vaccine with autism.”
This study “is the latest of more than 20…that have dismissed a link between the vaccine and autism, and is aimed at reassuring parents of the benefits of vaccinating against childhood diseases,” Bloomberg adds.
The 1998 study published in The Lancet “touched off a wave of anxiety among parents, including many who refused to inoculate their children, leading to an increase in U.S. measles cases this year.” Ian Lipkin, M.D., of Columbia University’s Mailman School of Public Health, and colleagues, pointed out that this study is the first “to rigorously examine MMR vaccination and autism.”
The researchers also noted that “the scientific community had not addressed” this “issue with definitive research, and this study was undertaken to fill that specific void.”
New York’s Newsday explains that “the study was not designed to address other rumored theories of autism’s cause, such as thimerosal, the much-debated mercury-based preservative in some other vaccines,” according to the authors.
Instead, it “replicated a controversial analysis by British physician Andrew Wakefield.” Dr. Wakefield’s theory “suggested measles viruses gravitate to the intestines where they persisted after vaccination, causing an inflammatory cascade that ultimately results in neurological damage and lifelong gastrointestinal (GI) disturbances.”
Therefore, during this study, the researchers “searched for traces of genetic material linked to the virus in intestinal tissue t aken from 25 children with autism and gastrointestinal problems. They compared the samples to those from 13 children without autism, but with intestinal problems.”
The investigators “found slight traces of measles-vaccine virus in only two” children, AHN noted. In addition, “only five of the 25 kids with autism got their MMR vaccine before getting bowel disease and autism.”
According to Dr. Lipkin, “the study confirmed that kids with autism often have ‘unrecognized and undertreated bowel complaints,'” WebMD added. Yet, while “he credited Dr. Wakefield with being the ‘first to recognize the importance of gastrointestinal disease in autism,'” Dr. Lipkin “insisted that MMR vaccination cannot account for this.”
In the Wall Street Journal’s Health Blog, Sarah Rubenstein quoted study co-author Mady Hornig, M.D., as saying, “Our results are inconsistent with a causal role for MMR vaccine as a trigger or exacerbator of either GI difficulties, or autism.”
Effectively, this study “eliminates the remaining support for the hypothesis that autism with GI complaints is related to MMR vaccine exposure,” she stated.
The AP and MedPage Today also covered the story.