Chiron Withdraws Measles Vaccine

Chiron Corporation (Emeryville, CA, www.chiron.com) is recalling and withdrawing its measles, mumps, and rubella (MMR) vaccine, "Morupar." Chiron supplied roughly 5 million doses of the Morupar vaccine in 2005 to a limited number of developing countries largely via the United Nations Children's Fund (UNICEF) and the Pan American Health Organization (PAHO), and supplied approximately 450,000 doses to Italy.

Chiron is recalling the vaccine as a precautionary measure following results of routine pharmacovigilance surveillance in Italy that suggest that Morupar may be associated with a higher reported rate of adverse events following immunization than other MMR vaccine products.

Chiron has been in communication with the relevant health authorities and informed them of its actions enable them to find replacement supplies of MMR vaccine. Chiron will work closely with the World Health Organization (WHO) to assist it in conducting a thorough risk-benefit analysis of the vaccine to determine whether it is appropriate for a limited quantity of the existing inventory to remain available for current public health programs such as those conducted by UNICEF and PAHO.

Chiron affirms support for Novartis deal

Separately, Chiron said it will continue to work toward completing its proposed merger with Novartis International AG (Basel, Switzerland, www.novartis.com) despite the continued opposition of one of its large shareholders, Value Act.

"We continue to believe that ValueAct should want to meet with Chiron's independent directors and management team to fully understand the serious challenges facing the Company and to gain a realistic perspective on our future prospects," said Chiron in a company statement. "Our independent directors and management team continue to strongly recommend the Novartis transaction and believe that it represents a full and fair price and is a superior alternative for Chiron's public stockholders to Chiron remaining a standalone company."