December 15, 2009
[efoods]Sanofi-Aventis SA recalled 800,000 doses of swine flu vaccine after testing showed the potency of the batches was too low, the U.S. Centers for Disease Control and Prevention said in a statement today.
Doctors who have unused shots from the batches should return them, the CDC said today. The shots remain safe, and people who have already been inoculated donâ€™t need to get revaccinated, according to the Atlanta-based agency.
The shots passed potency tests when they first shipped, and their potency dropped in subsequent tests by 10 to 12 percent, said Anne Schuchat, head of the National Center for Immunization and Respiratory Diseases at the CDC, in a telephone interview.