Chiron Corporation has reduced its supply expectations for its Begrivac influenza virus vaccine for the 2005-2006 influenza season by approximately 8 million doses and may delay shipments until early October.

Chiron had expected to supply approximately 12 million doses of Begrivac vaccine to customers outside of the United States. Chiron now expects to supply approximately 4 million doses of Begrivac vaccine in these markets. Begrivac vaccine is manufactured at Chiron's facility in Marburg, Germany.

According to the company release, in conducting its regular internal quality assurance tests, Chiron identified a small number of lots of the Begrivac vaccine that did not meet product sterility specifications. Chiron has taken presumptive corrective action, and is working closely with the German regulatory agency, the Paul Ehrlich Institute (PEI), to complete additional testing in order to determine the full extent of the issue. Chiron will not release any Begrivac vaccine until those tests are complete, the release says.