Inadvertent misadministration of meningococcal conjugate vaccine--United States, June-August 2005.

During June-August 2005, CDC and the Food and Drug Administration (FDA) were notified of seven clusters of inadvertent subcutaneous (SC) misadministration of the new meningococcal conjugate vaccine (MCV4, Menactra) (Sanofi Pasteur, Inc., Swiftwater, Pennsylvania), which is licensed for intramuscular (IM) administration only. A total of 101 persons in seven states were reported to have received MCV4 by the SC route. Of these, 100 were contacted by their health-care providers and advised of the administration error. CDC conducted an investigation to determine whether SC administration of MCV4 resulted in a protective immunologic response. This report describes the results of that investigation, which indicated that, despite the misadministration, persons vaccinated by the SC route were sufficiently protected and that revaccination was not necessary.