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Adverse effects from vaccination are rare, but children with weak immune systems need more attention, says IOM report

syringe82511.jpgToday, a committee from the US Institute of Medicine released its report on the adverse effects of vaccines, reviewing data from over 1,000 scientific papers. Many news sources reported on the main findings of the report, which is that vaccines are largely safe, and that the evidence does not support a link to autism or type 1 diabetes. The findings come at a time when parents and patients are more concerned about the adverse effects of vaccines than ever.

“Parents rate the safety of vaccines and drugs as the number one research priority that we have for children’s health,” says Matthew Davis, a pediatrician and professor of health policy at the University of Michigan in Ann Arbor who was not on the committee. “The new report may help families feel like they’re making a more informed decision.”

The report’s goal is to advise the Vaccine Injury Compensation Program, a government service administered by the US Department of Health and Human Services, which doles out payment to people demonstrably injured by vaccines. The IOM’s review out today should help workers in the program decide whether a medical problem is a true side effect of vaccination, increasing the program’s efficiency, says Clay Johnston, an epidemiologist at the University of California, San Francisco who served on the committee. “If there are clear associations between a symptom and a vaccine, you know that you can compensate those people,” he says, adding that the occurrence of such adverse events are rare.

But the report also acknowledged that although the risk from vaccines is small, certain people are more at-risk than others. In particular, immunodeficient individuals are more likely to develop complications resulting from live-virus vaccines. By adulthood, most people know whether they have an immune system problem, and those who do will not receive flu shots. In comparison, infants are less likely to show signs of immune weakness before their first shots, and that’s where the danger lies.

“If you have one of these rare [immunodeficient] conditions, live vaccines can be lethal,” says Jennifer Puck, a pediatric immunologist at the University of California, San Francisco. “It’s one of the important reasons to institute newborn screening for the severe diseases that can be detected these days.”

Some states have already mandated screening for immunodeficiencies in infants. In May 2010, health secretary Kathleen Sebelius added severe combined immunodeficiency (SCID), a genetic disorder causing a highly compromised immune system, to her recommended panel of tests administered at birth. In reaction, five states have picked up the banner — Wisconsin, Massachusetts, California, Louisiana and New York — requiring a test for this immunodeficiency before newborns leave the hospital.

Puck herself found seven cases of SCID in otherwise-healthy infants last year in enough time to cancel their vaccinations and give them a life-saving bone marrow transplant, validating the use of these tests. But more states need to start mandating immune tests in infants, she says. “Hospitals just have to gear up to run one more test on that same sample” taken for the basic battery of newborn tests, she says. “It’s not difficult to do as these five states have shown.”

The report highlights the areas that need more research, including immunodeficiency diagnosis and other risk areas, says Louis Cooper, professor emeritus of pediatrics at Columbia University College of Physicians & Surgeons in New York. “The report is very clear in laying out where there are gaps in our knowledge and can serve as a useful tool for scientists as they design their studies,” he says. “It will help us to shape the resources and the mechanisms and the structure that will allow us to fill in the gaps we know about now.”

Image: via Flickr user Andres Rueda under Creative Commons

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