Vaccination Safe for Kids With Genetic Disorders

Oct. 30, 2009 (Philadelphia) -- Vaccination does not appear to cause autism or other health problems, even in children with certain genetic disorders, a new study suggests.

Experts say the finding is noteworthy because in 2007 the Department of Health and Human Services conceded that vaccination could have aggravated a child's underlying mitochondrial disorder and caused her autism symptoms.

Mitochondrial disorder is one of a group of over 90 rare genetic disorders known collectively as inborn errors of metabolism. Other examples include phenylketonuria (PKU) and Tay-Sachs disease.

"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," says researcher Nicola Klein, MD, PhD, of the Kaiser Permanente Vaccine Study Center in Oakland, Calif. "But we found no increase in emergency room visits or serious side effects" among children with inborn errors of metabolism, she tells WebMD.

Klein and colleagues examined Northern California Kaiser Permanente’s medical records and identified about 75 children who were diagnosed with an inborn error of metabolism from 1990 to 2007. Then, their immunization and health records were compared with those of more than 1,500 healthy children of the same ages. Results showed there was no difference in the proportion of children who were up to date for all their shots by age 2.

The researchers then looked at how many times about 250 children with an inborn error of metabolism, seven of whom had mitochondrial disorder, had been hospitalized or rushed to the ER in the 30 days after receiving any vaccine. That figure was compared to how many times they were hospitalized or sent to the ER in the second month after vaccination.

There was no difference, Klein says. "If the vaccine was causing any problems, we would expect to see them emerge right around the time of vaccination, not a month later."

While preliminary, the findings "are very reassuring," says Emory University's Larry Pickering, MD, a senior advisor to the CDC's National Immunization Program.

Pickering moderated the session at which the study was presented at the annual meeting of the Infectious Diseases Society of America.

"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. They are at increased risk for devastating complications, even death, from the diseases that the vaccines prevent," he tells WebMD.