- Copyright © 2001 by the American Academy of Pediatrics
Countering media reports on the alleged link between autism and measles-mumps-rubella (MMR) vaccine has been an uphill battle for many pediatricians.
“It’s compelling when you see a parent come on TV and say, ‘My child was fine and then a week after he got the MMR shot, he developed autism,’” said Jon Abramson, M.D., FAAP, chair of the AAP Committee on Infectious Diseases.
Pediatricians now have several new pieces of ammunition to help convince parents that the vaccine is safe.
The first is a report from a multidisciplinary panel of experts convened by the Academy to review data on possible associations between MMR vaccine and autistic spectrum disorder (ASD). The panel also examined information on a possible relationship of measles virus and/or vaccine and inflammatory bowel disease (IBD).
The report concludes, “The available evidence does not support the hypothesis that MMR vaccine causes autism or associated disorders or IBD” (Pediatrics. 2001;107:e84OpenUrl). It also says pediatricians need to work with families to ensure children are protected from these preventable diseases.
“Pediatricians should feel comfortable using MMR vaccine and recommending it for their patients,” said Neal A. Halsey, M.D., FAAP, co-chair of the panel that wrote the 64-page report.
The panel included experts in general and developmental pediatrics, child neurology, pediatric infectious diseases, virology, pathology, public health, epidemiology and psychiatry. It reviewed information and research presented by parents, practitioners and scientists at an AAP-sponsored conference last June. After the conference, the writing panel reviewed materials submitted by invited speakers who did not attend the conference as well as more than 1,000 references in the medical literature.
“We did not go into this with a preconceived notion of what the results should be,” said Susan Hyman, M.D., FAAP, co-chair of the writing panel. “This group went into this with the intent of casting an extraordinarily broad net, so that the basic science, the epidemiology, the clinical science related to diagnosis were all taken into account.”
The group also concluded that more research is needed to identify the causes of ASD, a continuum of disorders with symptoms related to reciprocal social interaction, communication and restricted interests.
“What we hoped to do was to synthesize a very broad set of scientific and medical topics that physicians would not typically access, so that they will be able to review where research is needed and what information we have available to us,” Dr. Hyman said.
One of the most recent studies referenced in the report appeared in the March 7 issue of the Journal of the American Medical Association. Researchers examined California data on early childhood MMR immunization levels from 1980 through 1994 along with data on autism caseloads in the same period. They concluded the data do not suggest an association between MMR immunization among young children and an increase in autism occurrence (Dales L, Hammer SJ, Smith JN. JAMA. 2001;285:1183-1185OpenUrlCrossRefPubMedWeb of Science).
Another recently published study found the risk of autism in the United Kingdom increased nearly fourfold among boys ages 2 to 5 years born in 1988-1993, whereas the prevalence of MMR vaccination was over 95% and virtually constant (Kaye JA, del Mar Melero-Montes M, Hershel J. BMJ. 2001;322:460-463OpenUrl).
The public’s concern about a possible connection between MMR immunization and ASD is based largely on the work of British researcher Andrew Wakefield, M.D., and his colleagues. In 1998, The Lancet published their study, which investigated the relationship between MMR vaccine and inflammatory bowel disease in 12 children with regressive developmental disorder.
“In susceptible children (possibly for reasons of age, immune status or genetic background) MMR vaccine is an atypical pattern of measles exposure that represents a significantly increased risk for intestinal infection and associated developmental regression compared with the monovalent vaccine or natural infection,” Dr. Wakefield wrote in a statement to the panel.
Dr. Wakefield has advocated for the administration of monovalent measles, mumps and rubella vaccines, because he believes simultaneous administration might lead to persistent infection or alteration of the clinical and immune response to the antigens.
Dr. Wakefield’s research has received much media attention in the United Kingdom and the United States. The UK government early this year announced a $4.4 million campaign to reassure parents that the MMR vaccine is safe.
The panel convened by the Academy also concluded in its report that “separate administration of measles, mumps and rubella vaccines to children provides no benefit over administration of the combination MMR vaccine and would result in delayed or missed immunizations.”
Dr. Hyman suggests pediatricians read the entire report so they can use the information when they talk to families about MMR vaccine.
“If a physician was to say in a blanket fashion, ‘There is no relationship (between MMR vaccine and autism),’ that is an immediate closing of the door,” Dr. Hyman said. “If the physician goes through with the family and shares with them his or her understanding of the review that we did and does it in a respectful fashion, then I think the family and the physician will be able to problem solve.”