MedImmune Recalls 4.7 Million Doses of H1N1 Vaccine Because of Drop in Potency

MedImmune, a division of AstraZeneca (London, UK), yesterday recalled 13 lots (4.7 million doses) of its nasal spray H1N1 (swine) flu vaccine, because of a drop in potency.

MedImmune, a division of AstraZeneca (London, UK), yesterday recalled 13 lots (4.7 million doses) of its nasal spray H1N1 (swine) flu vaccine, because of a drop in potency.

The company detected the slight decline in potency as part of its routine stability testing, and notified the Centers for Disease Control and Prevention (CDC) and the US Food and Drug Administration on December 16 and 21. The vaccine in these lots is still expected to be effective in stimulating immunity, however, so people who received vaccinations from those lots do not need to be re-vaccinated.

Most of the affected doses were shipped in the first few weeks of H1N1 vaccination, when the vaccine's potency was still at or above the specification limit.

Sanofi-Aventis SA (Paris, France) recalled 800,000 doses of its pediatric H1N1 flu vaccine on December 15, also because of a drop in potency detected during stability studies.