WASHINGTON – About 800,000 doses of swine flu vaccine for children are being recalled because tests found the strength of the shots had dropped, officials announced Tuesday.
The recall was being done as a precaution and not because the vaccine poses any safety threat, officials said. Children who already received the vaccine are believed to have gotten full protection, officials said.
"This is a non-safety-related recall," said Anne Schuchat, director of the federal Centers for Disease Control and Prevention’s National Center for Immunization and Respiratory Diseases. "There are not any implications for parents and the public. But we are providing a heads-up to providers about this."
Most of the vaccine, which was distributed nationwide in November when demand was high, has probably already been used.
Although the shots’ potency had dropped since shipment, the doses were still considered strong enough to provide adequate protection, especially if children receive their second normal booster shot, Schuchat said.
"We don’t think there’s any harm to anyone who has gotten this," Schuchat said. "In fact, we think the vaccine probably would have worked. They probably got good responses."
The affected vaccine was a produced by Sanofi Pasteur, one of the major makers of the H1N1 vaccine, and included only pre-filled syringes containing 0.25 milliliters for children 6 to 35 months old. The syringes did not contain the preservative thimerosal, which some parents have been reluctant to give their children because of unconfirmed fears that it may be linked to autism.
The vaccine passed all required tests before it was shipped, but one lot was found to have dropped in potency during follow-up quality-control testing the company routinely performs. That prompted additional testing, which discovered a similar drop in potency in three other lots, officials said.
No similar problems have been found for other lots or formulations, including the nasal spray, single-syringe doses for older children or multi-dose vials for children and adults.
The cause of the potency drop is being investigated, Schuchat said.