Sanofi initiated a recall of 800,000 doses of swine flu vaccine after testing indicated the doses were not potent enough to protect against the virus.
The recalled shots were preservative-free syringes of a low-dose version made for children between the ages of 6 – 25 months, according to the National Center for Immunization and Respiratory Diseases at the CDC.
Health officials are unable to determine how many doses have already been given, however there is no safety concern, said the agency. Those children vaccinated from the recalled lots will not need to be re-vaccinated.
Swine flu has killed an estimated 10,000 Americans since it first emerged in March and has hospitalized more than 200,000, according to the CDC.
Need more information about Swine Flu and the latest news? Read several of our other articles that cover the topic in detail.