O-STA

Chiron Corporation Donates 9.5 Million Vaccine Doses to Polio Global Eradication Initiative

EMERYVILLE, Calif. (ots) - Delivery will fulfill company's pledge to help eradicate polio through the contribution of more than 30 million vaccine doses

Chiron Corporation (Nasdaq: CHIR) announced today that the company's vaccine business unit will donate 9.5 million doses of poliomyelitis (polio) vaccine to the polio Global Eradication Initiative during the summer months. The donation will fulfill Chiron's 1996 commitment to donate 30 million doses of polio vaccine to the Initiative for international vaccination campaigns.

"Chiron Vaccines made an ambitious pledge to help eradicate this crippling disease, and we are so proud to demonstrate that we will fulfill that pledge," said John Lambert, president, Chiron Vaccines. "At Chiron, we are committed to making a difference in people's lives. We feel that this vaccine program is one very tangible way to live up to our commitment."

The Global Eradication Initiative, launched in 1988, is spearheaded by the World Health Organization (WHO), Rotary International, the U.S. Centers for Disease Control and prevention (CDC) and UNICEF. Chiron Vaccines joined the initiative in 1996, and provided more than 20 million doses of polio vaccine to the WHO and UNICEF between 1997 and '98.

The World Health Organization (WHO) has targeted 2005 as a global eradication date for polio. The donation announcement made by Chiron coincides with the June 21 announcement by the European Regional Commission for the Certification of Poliomyelitis Eradication that Europe is officially polio-free.

"Polio-free Europe is one tremendous step toward eradication of this disease," said Lambert. "However, polio is an extremely infectious disease, and the growing mobility of the world's population creates the risk that polio will be re-introduced to countries where it has previously been eradicated. Through the donation of high-quality vaccines, Chiron is pleased to be helping ensure that the Eradication Initiative achieves its goal of European eradication by 2005."

About Chiron Vaccines

Chiron Vaccines, the fifth largest vaccine business in the world, currently markets more than 30 novel and conventional vaccines for adults and children throughout the world. . The mission of Chiron Vaccines is to bring to the market, through innovation and creativity, biological solutions needed for the prevention and treatment of infectious disease. Every second, 25 people across more than 70 countries of the world are vaccinated with a Chiron vaccine.

About Chiron Corporation

Chiron Corporation, headquartered in Emeryville, California, is a global pharmaceutical company that leverages a diverse business model to develop and commercialize high-value products that make a difference in people's lives. The company has a strategic focus on cancer and infectious disease. Chiron applies its advanced understanding of the biology of cancer and infectious disease to develop products from its platforms in proteins, small molecules and vaccines. The company commercializes its products through three business units: Biopharmaceuticals, vaccines and blood testing. For more information about Chiron, visit the company's website at http://www.chiron.com.

Contact:

In the United States

John Gallagher

Chiron Corporation (USA)

Media Relations Manager

+1.510.923.6905

In Germany

Dr. Brigitte Wolter

Chiron Behring GmbH & Co (Germany)

Head of Public Affairs / Corp. Comm.

+49 6421 39 3265