Chiron to Testify Today to the Value of Influenza Vaccination Before U.S. Senate Special Committee on Aging.

EMERYVILLE, Calif. -- President and CEO Howard Pien Reiterates Supply Expectations Of Fluvirin(R) Influenza Virus Vaccine as Stated in August

Chiron Corporation (Nasdaq:CHIR) announced that president and chief executive officer Howard Pien will appear before the U.S. Senate Special Committee on Aging in Washington, D.C., today in a hearing titled, "Combating the Flu: Keeping Seniors Alive." Mr. Pien will speak on the value of influenza vaccine in protecting health, the importance of raising awareness of the benefits of vaccination, and the need to prepare for an influenza pandemic.

Mr. Pien will also reiterate Chiron's expectation, as stated in the company's August 26, 2004, press release, that it will supply between 46 million and 48 million Fluvirin(R) influenza virus vaccine doses to the U.S. market for the 2004-2005 influenza season, beginning in early October. The planned late-season delivery of 2 million Fluvirin doses for a national stockpile held by the U.S. Centers for Disease Control and Prevention (CDC), not included in the totals above, remains on schedule as well. Since its August announcement, Chiron has worked closely with government agencies to keep them informed of its retesting process. The results of the confirmatory testing to date are consistent with the company's shipping expectations. Following compilation and formal sign-off of its test data, Chiron expects to complete its discussions with regulatory authorities and proceed with releasing Fluvirin to the U.S.…