No Link Between MMR Vaccination And Autism

LONDON, ENGLAND -- June 11, 1999 -- A population-based study reported in this week's issue of The Lancet has found no evidence to support the hypothetical link between measles, mumps and rubella (MMR) vaccination and autism.

Professor Brent Taylor and colleagues, from the Royal Free and University College Medical School and the Public Health Laboratory Service Communicable Disease Surveillance Centre in London, England, identified 498 children with autism from special needs and disability registers in eight North Thames health districts. They found no evidence to support an association of MMR with autism.

The investigation showed that the number of cases of autism has been increasing since 1979, but there was no sign of a sharp increase after MMR vaccination was introduced in 1988. Second, the average age of affected children at diagnosis of autism was the same for those who had been vaccinated before they were 18 months old as for those who had never received MMR or who were vaccinated after age 18 months. Third, the proportion of children vaccinated was nearly identical for the group with autism and for the general population of children in the whole region. Fourth, there was no clustering of regression (when an apparently normal child starts to behave as if much younger) in the months after MMR vaccination.

No Connection Between MMR Vaccine and Autism Detected

A recently published study conducted in the United Kingdom found no association between immunization with the measles, mumps, and rubella (MMR) vaccine and autism in children. Previous media reports suggesting such a connection may have caused undue parental concern. Autism, an uncommon condition, does not have clearly understood causes. Only about 5 of every 10,000 children are diagnosed with the most common type of autism called typical autism. These children frequently develop normally until around age 2, when socialization and language skills begin to deteriorate. Severely autistic children often become very withdrawn, and may be unable to appropriately respond to their surroundings, including family members.

A total of 498 children who were born in a region of the United Kingdom between 1979 and 1992 were identified as having autism. Of the 389 children with autism who were born after 1987, about 90% had been immunized with the MMR vaccine. Although there was a steady yearly increase in the number of children diagnosed with autism until the mid-1990s, no sudden change in the incidence of autism after the introduction of the MMR vaccine occurred.

The previous study implying a link between autism and MMR immunization suggested that the vaccine might trigger the deterioration of social and language skills that occurs after a normal course of development in about one third of children diagnosed with typical autism. Many parents reported that they had become concerned about their child's developmental delays around the time the child was 18 months of age. Because most children had received the MMR vaccination a few months before, this created the appearance of a possible connection between the immunization and the development of autism symptoms. This study found no association between MMR immunization and the appearance of autistic symptoms during the 6 months following the vaccination.

What This Means to You: This study did not indicate a relationship between the measles, mumps, and rubella (MMR) vaccine and autism in children. Failure to immunize against measles and other vaccine-preventable diseases puts children at risk for developing severe complications of these illnesses, including death. The American Academy of Pediatrics recommends that children receive their first MMR vaccination between 12 and 15 months of age.

Source: THE LANCET, June 12, 1999

Reviewed by: Steve Dowshen, MD
Date reviewed: July 1999

Thursday January 10 5:35 PM ET

Fatty Acid-Fortified Baby Formula
to Be Sold in US

By Suzanne Rostler

NEW YORK (Reuters Health) - Infant formulas containing two fatty acids necessary for neurological and visual development will be available for the first time in the US early this year, infant formula manufacturers announced Thursday.

The compounds, docosahexaenoic acid (DHA) and arachidonic acid (AA), are long-chain polyunsaturated acids that appear to boost brain development and improve vision. They are present in breast milk and in infant formulas in some European countries but are not currently found in formulas sold in the United States.

The new formulas, marketed by Mead Johnson Nutritionals, a division of Bristol-Myers Squibb, and the Ross Products division of Abbott Laboratories are expected to cost about 15% to 20% more than formulas without the fatty acids, the two companies said.

But while the addition of the compounds has been shown to boost blood levels of the essential fatty acids, it is not clear whether higher blood levels translate into any developmental benefit. Studies, said Dr. Frank R. Greer, a professor of pediatrics at the University of Wisconsin-Madison, have had mixed results.

``The overall strategy is to make formula more like human milk and by adding these long-chain fatty acids, you make formula, at least from a compositional standpoint, more like human milk,'' Greer told Reuters Health. ``It doesn't do any harm but whether it helps term babies is questionable.''

Dr. William MacLean, vice president of medical and regulatory affairs with Ross Products, said that two large studies conducted by Abbott Laboratories concluded that there was no difference in the neurological and visual development of infants fed formula with and without the compounds in full-term, healthy infants. Pre-term infants, on the other hand, showed an improved rate of visual development when they were fed formula containing DHA and AA, he told Reuters Health.

Other studies have shown a benefit for full-term babies. In one report, infants who had been fed formula supplemented with DHA and AA scored better on a test assessing complex problem-solving skills, compared with infants fed formula that was not supplemented, at 10 months of age. Other studies have shown more rapid rates of visual development in infants fed DHA- and AA-enriched formula.

``Since rapid infant brain development occurs in the early months of life, a number of researchers believe that a direct dietary source of DHA and AA at that time can be beneficial for brain and retinal development,'' said Dr. James W. Hansen, a neonatologist and medical director for Mead Johnson Nutritionals, in a prepared statement.

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Infants Can Handle Multiple Vaccines: Experts

By Amy Norton

NEW YORK (Reuters Health) - Despite some parents' concerns, infants' immune systems are strong enough to handle the many vaccinations they should receive in their first months and years of life, US experts say.

In the January issue of Pediatrics, researchers lay out the evidence that even newborns have sturdy immune systems and that receiving multiple vaccinations does not ``overwhelm'' babies' defenses.

Some recent surveys have indicated that this is a concern for many parents, according to Dr. Paul A. Offit of Children's Hospital of Philadelphia, Pennsylvania, and his colleagues.

``I think it's an understandable concern,'' Offit said in an interview with Reuters Health. For parents, he added, the sight of the multiple needle sticks their babies get at an office visit may seem more threatening than the invisible pathogens vaccines ward off.

Today in the US, children receive 11 routine vaccinations and as many as 20 shots by age 2, Offit and his colleagues note. These immunizations protect against a range of potentially serious infections such as measles, mumps, chicken pox and hepatitis B.

But the sheer number of shots children get has made some parents question whether their young immune systems can withstand it all.

They can, Offit said. Long before birth, he and his colleagues explain, the immune response takes shape, with key immune-system cells called B cells and T cells showing up by the 14th week of pregnancy.

Vaccines prime the immune system to fight certain infections by exposing it to antigens, or proteins, from a virus or bacterium. This allows the body to produce antibodies to the germ, which will protect the child from infection.

According to Offit and his colleagues, an infant's immune system has the ``theoretical capacity'' to respond to roughly 10,000 vaccines at any one time. They estimate that if a baby received all 11 available vaccines at once, this would ``use up'' 0.1% of the immune system.

And in reality, they explain, ``a vaccine never really 'uses up' a fraction of the immune system'' because the child's B cells and T cells are constantly replenished.

Compared with the vast exposure children have to microbes in their environment and in their own bodies, Offit said, ``a vaccine is just a drop in the ocean.''

In addition, he and his colleagues point out, although the number of vaccines children receive shot up over the last century, the number of antigens in these vaccines has declined. The one vaccine children received 100 years ago--the smallpox vaccine--contained 200 proteins. Today's recommended 11 vaccines contain around 130 proteins in total.

Offit explained that advances in the way vaccines are created have allowed this sharp decline.

``Current studies do not support the hypothesis that multiple vaccines overwhelm, weaken, or 'use up' the immune system,'' he and his colleagues write.

Instead, they conclude, ``by providing protection against a number of bacterial and viral pathogens, vaccines prevent the 'weakening' of the immune system.''

SOURCE: Pediatrics 2002;109:124-129.

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