Childhood Vaccines Safe, Review Shows
Dozens of Studies Show Thimerosal, Other Additives Don't Harm Kids
WebMD News Archive
Dec. 8, 2003 - Parents concerned about the safety of flu shots and other vaccines given to children should be reassured by a newly published review of dozens of scientific studies. A leading pediatric infectious disease expert says the review offers "overwhelming" evidence that the vaccines are both effective and safe.
The pronouncement comes at a time when millions of parents are deciding if they should have their children vaccinated against a flu outbreak, which is hitting children especially hard this season.
The flu vaccine is one of the few immunizations given to children still containing the controversial mercury-derived preservative thimerosal. But vaccine advocate Paul Offit, MD, says there is little reason for worry. Offit is chief of infectious diseases at Children's Hospital of Philadelphia.
"The concerns about thimerosal have centered around its use in children less than 6 months of age, but the flu vaccine is not given to children under 6 months," he tells WebMD. "And the level of thimerosal in the influenza vaccine is very small -- well below the level considered safe for children."
For more than a decade, antivaccine activists have charged that the thimerosal in childhood vaccines is to blame for a dramatic worldwide rise in the diagnosis of autism. The concerns led to the removal of thimerosal from most childhood vaccines a few years ago. Offit says the action was taken to calm parents' fears, even though there was virtually no scientific evidence supporting the link between vaccines and autism.
Preservatives are used in vaccines to prevent contamination. They were added in the 1920s after children developed severe and sometimes fatal infections after receiving contaminated vaccines.
In his review, published in the December issue of Pediatrics, Offit pooled the studies examining the safety of thimerosal and other vaccine additives, such as aluminum, formaldehyde, gelatin, and egg and yeast proteins.
He says the studies overwhelmingly point to the safety of childhood immunizations, with the exception of rare allergic reactions to the gelatin and egg products used in some vaccines.
"It is no surprise that parents become concerned when they hear that a vaccine contains mercury or aluminum," Offit tells WebMD. "But anyone who lives on the face of the earth is exposed to heavy metals, and the trace amounts used in these vaccines have been shown to be safe. Vaccines are the safest, best tested things that we put into our bodies, and choosing not to have your child vaccinated is not risk free."