Source: DGNews  |  Posted 2 years ago

By Ed Susman

PHILADELPHIA -- November 1, 2009 -- Vaccine inoculations show no link to autism or other health problems even in children with certain genetic disorders that might put them at risk for such problems, researchers stated here at the 47th Annual Meeting of the Infectious Diseases Society of America (IDSA).

The research findings could contradict previous concessions by the US Department of Health and Human Services that suggested a possibility that vaccination might have aggravated a child’s underlying mitochondrial disorder and caused her autism symptoms.

“After that ruling, there was some concern that vaccination may place some children with genetic disorders at increased risk for autism or other adverse effects,” said Nicola Klein, MD, Kaiser Permanente Vaccine Study Center, Oakland, California, on October 30. “But we found no increase in emergency room visits or serious side effects” among children with inborn errors of metabolism.

Dr. Klein and colleagues looked over the medical records accumulated by the Northern California Kaiser Permanente and identified 79 children who were diagnosed with an inborn error of metabolism from 1990 to 2007. The researchers then matched those children with their immunisation and health records and compared them with the vaccination records of more than 1,580 healthy children of the same age.

Results showed there was no difference in the proportion of children who were up-to-date for all their shots by age 2. “Although sample size is a limitation, preliminary evidence does not suggest an association between vaccination and an increased risk for serious adverse events,” Dr. Klein said.

In a separate analysis, doctors identified 250 children with an inborn error of metabolism -- 7 of whom had mitochondrial disorder -- who had been hospitalised or rushed to the emergency room in the 30 days after receiving any vaccine. That figure was compared with how many times they were hospitalised or sent to the emergency room in the second month after vaccination. Dr. Klein said there appeared to be no difference in these rates. The preliminary figures showed a nonsignificant 17% reduction in visits to the emergency room and a nonsignificant 10% increase in hospitalisations.

“If the vaccine was causing any problems, we would expect to see them emerge right around the time of vaccination, not a month later,” she explains.

“These findings are very reassuring,” said Larry Pickering, MD, National Immunization Program, Centers for Disease Control and Prevention, and Emory University, Atlanta, Georgia, who moderated the session at which the study was presented.

“Most of us who take care of kids with inborn errors of metabolism think vaccination is one of the best interventions we can offer them,” he said. “They are at increased risk for devastating complications, even death, from the diseases that the vaccines prevent.”

[Presentation title: Evaluation of Immunization Rates and Safety Among Children With Inborn Errors of Metabolism. Abstract 187]