FDA and CDC have been notified by Aventis Pasteur of a recent Quality Assurance test that revealed the presence of non-inactivated Pitman-Moore virus (the attenuated vaccine strain) in a single product lot. IMOVAX is an inactivated viral vaccine and should not contain live virus. This above-mentioned lot was not distributed. As a precautionary measure, Aventis Pasteur has decided to initiate a voluntary recall of lots which were produced during the same time period. Recalled lots passed all release tests, including testing to confirm the absence of live virus, and no unusual adverse events associated with the recalled vaccine have been reported.