Sanofi Pasteur Recalls 800,000 Doses of Pediatric H1N1 Vaccine Due to Deficient Antigen Levels

Emma Hitt, PhD


December 15, 2009

December 15, 2009 — Sanofi Pasteur is recalling approximately 800,000 doses of its pediatric influenza A (H1N1) monovalent vaccine in a single-dose, prefilled syringe (0.25 mL) because antigen content is lower than required levels, the Centers for Disease Control and Prevention (CDC) announced today.

The doses are part of 4 lots shipped in November and are intended for children aged 6 to 35 months.

Sanofi Pasteur notified the CDC and the Food and Drug Administration (FDA) after testing 1 lot and later finding 3 additional lots that had deficient antigen levels.

According to a CDC health update, the CDC and the FDA agree that the "small decrease in antigen content is unlikely to result in a clinically significant reduction in immune response among persons who have received the vaccine."

"For this reason, there is no need to revaccinate persons who have received vaccine from these lots," they note.

The following lots are affected and should be returned to the manufacturer unused:

  • 0.25-mL prefilled syringes, 10-packs (NDC 49281-650-25, sometimes coded as 49281-0650-25): UT023DA, UT028DA, and UT028CB; and

  • 0.25-mL prefilled syringes, 25-packs (NDC 49281-650-70, sometimes coded as 49281-0650-70): UT030CA.

According to the CDC and the FDA, no safety concerns have been associated with the reduced antigen content. In addition, the decrease is considered only slightly below the required level, and levels met specifications when the vaccine was distributed, the update states.

All children younger than 10 years should get the recommended 2 doses of H1N1 vaccine approximately 1 month apart for optimal immune response.

Questions and answers regarding the withdrawn vaccine are available on the CDC Web site.

Adverse events related to the pediatric influenza A (H1N1) monovalent vaccine in a single-dose, prefilled syringe (0.25 mL) should be communicated to MedWatch by telephone at 1-800-FDA-1088, by fax at 1-800-FDA-0178, online at, or by mail to 5600 Fishers Lane, Rockville, Maryland 20852-9787.


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