The CDC has recalled certain lots of pediatric H1N1 vaccines from the market. These vaccines include pre-filled syringes for 6-35 month olds. Should infants and children who received vaccines from these lots be revaccinated? The Centers for Disease Control and Prevention has a detailed Questions & Answers article for reference.

Why are some lots of pediatric H1N1 vaccine manufactured by Sanofi Pasteur in pre-filled syringes being recalled from the market?

According to the Centers for Disease Control and Prevention, “As part of its quality assurance program, the manufacturer, Sanofi Pasteur, performs routine, ongoing stability testing of its H1N1 vaccine after the vaccine has been shipped to providers. Stability testing means measuring the strength of a vaccine over time. It is performed because sometimes the strength of a vaccine can go down over time. On December 7, Sanofi Pasteur notified CDC and FDA that the potency in one batchof pediatric syringes that had been distributed was later found to have dropped below a pre-specified limit. As a result of this finding, Sanofi Pasteur tested additional lots and found that three other lots that had been distributed also had an antigen content that, while properly filled at the time of manufacturing, was later measured to be below pre-specified limits.”

For more information, and to read the entire Swine Flu Vaccine Alert, go to Centers for Disease Control and Prevention, 1600 Clifton Rd. Atlanta, GA 30333, USA 800-CDC-INFO (800-232-4636) TTY: (888) 232-6348, 24 Hours/Every Day – cdcinfo@cdc.gov