FEBRUARY 24, 2004

Dynavax Announces Exercise of Underwriters' Over-Allotment Option

FOR IMMEDIATE RELEASE

BERKELEY, Calif., Feb. 24 /PRNewswire-FirstCall/ -- Dynavax Technologies Corporation (Nasdaq: DVAX), today announced that the underwriters of its previously announced initial public offering of 6,000,000 shares of common stock have fully exercised their over-allotment option and acquired 900,000 common shares to cover over-allotments. Total net proceeds to the Company from the exercise of the over-allotment option were $6,277,500. Bear, Stearns & Co. Inc. and Deutsche Bank Securities were joint book-running manaSxgers for the offering, with Piper Jaffray & Co. as co-manager. Copies of the final prospectus relating to the offering may be obtained from Bear, Stearns & Co. Inc. at 383 Madison Avenue, New York, New York 10179, 212-272-2000 and from Deutsche Bank Securities at 60 Wall Street, 4th Floor, New York, New York 10005.

A registration statement relating to these securities was declared effective by the Securities and Exchange Commission on Feuary 11, 2004. The public offering is being made by means of a prospectus. This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

Dynavax Technologies Corporation discovers, develops, and intends to commercialize innovative products to treat and prevent allergies, infectious diseases, and chronic inflammatory diseases using versatile, proprietary approaches that alter immune system responses in highly specific ways. Our clinical development programs are based on immunostimulatory sequences, or ISS, which are short DNA sequences that enhance the ability of the immune system to fight disease and control chronic inflammation.

This release contains forward-looking statements that are subject to risks and uncertainties. Although Dynavax Technologies Corporation believes that the expectations reflected in its forward-looking statements are reasonable, actual results could differ materially from those expectations. Important cautionary statements and risk factors that would affect actual results are discussed in materials filed by Dynavax Technologies Corporation with the Securities and Exchange Commission.

About Dynavax Technologies Dynavax Technologies is a privately held biopharmaceutical company developing innovative products to treat allergy, inflammation-mediated diseases, infectious diseases and cancer. The company’s lead products are based on ImmunoStimulatory Sequences (ISS), short DNA sequences that enhance the ability of the immune system to fight disease and prevent inflammation. The company’s two most advanced products are AIC, which has provided positive results in recently completed phase II clinical trials for the treatment of ragweed allergy, and a next-generation hepatitis B vaccine that may offer single-dose protection. Dynavax is also developing an oral TNF-alpha synthesis inhibitor initially for the treatment of rheumatoid arthritis. The company has collaborations with Aventis-Pasteur, Triangle Pharmaceuticals and Stallergenes.

Contact: Andrew Gengos Chief Financial Officer Dynavax Technologies Corporation (510) 848-5100

Note: This press release contains "forward looking statements" within the meaning of the federal securities laws. These forward-looking statements include without limitation, statements relating to the potential success of product development, subsequent regulatory approvals and potential product sales. These statements are subject to risks and uncertainties that could cause actual results and events to differ materially from those anticipated. Readers are cautioned not to place undue reliance on these forward-looking statements that speak only as of the date of this release. Dynavax undertakes no obligation to update publicly any forward-looking statements to reflect new information, events or circumstances after the date of this release except as required by law.