Clover and Dynavax Announce Commercial Supply Agreement of Dynavax's CpG 1018 Adjuvant for Clover's COVID-19 Vaccine Candidate

Clover to procure CpG 1018 adjuvant from Dynavax for use in the commercial production of Clover's COVID-19 vaccine candidate,SCB-2019 (CpG 1018/Alum)

Pending conditional regulatory approvals,Clover expects to commence product launch of SCB-2019 (CpG 1018/Alum) by the end of 2021

CHENGDU,China and EMERYVILLE,Calif.,June30,2021 -- Clover Biopharmaceuticals (Clover),a global clinical-stage biotechnology company developing novel vaccines and biologic therapeutic candidates to address the world's most life-threatening diseases and public health threats,and Dynavax Technologies Corporation (Dynavax,Nasdaq: DVAX),a biopharmaceutical company focused on developing and commercializing novel vaccines,today announcedthe execution of a commercial supply agreement of Dynavax's CpG 1018TM advanced adjuvant,for use in Clover's protein-based COVID-19 vaccine candidate,SCB-2019 (CpG 1018/Alum). Thecommercialsupplyagreementextendstotheendof2022. The agreement includes doses for delivery in 2021,which were manufactured under the previously announced funding agreement between Coalition for Epidemic Preparedness Innovations(CEPI) and Dynavax.

Clover separately announced today an advanced purchase agreement with Gavi,the Vaccine Alliance,for supplying up to 414 million doses of SCB-2019 (CpG 1018/Alum) through 2022 for the COVAX Facility. The COVAX Facility is a global risk-sharing mechanism for pooled procurement and equitable distribution of COVID-19 vaccines,regardless of income level. Pending conditional regulatory approvals,Clover expects to commence product launch of SCB-2019 (CpG 1018/Alum) by the end of 2021,supplying the COVAX Facility and countries directly via government procurement and/or bilateral supply agreements.

"Throughout the development of our COVID-19 vaccine candidate,Dynavax has been an invaluable partner with a shared goal of maximizing our collective impacts in fighting the unprecedented COVID-19 pandemic. We look forward to the continued partnership as we accelerate large-scale production of SCB-2019 (CpG 1018/Alum) for potential commercial supply to communities in need around the globe," stated Joshua Liang,Chief Executive Officer of Clover Biopharmaceuticals.

Ryan Spencer,Chief Executive Officer of Dynavax commented,"Dynavax is excited for the opportunity to expand our partnership with Clover into an important commercial supply agreement to provide significant amounts of CpG 1018 for combatting the ongoing pandemic. We are proud to support the ongoing development and the potential near-term commercialization of SCB-2019 (CpG 1018/Alum)."

About SCB-2019 (CpG 1018/Alum)

SCB-2019 (CpG 1018/Alum),Clover's COVID-19 vaccine candidate,is anticipated to be one of the first commercialized protein-based COVID-19 vaccines globally through the COVAX Facility. Employing the Trimer-Tag© technology platform,Clover developed the SCB-2019 antigen,a stabilized trimeric form of the S-protein (S-Trimer) based on the original strain of the SARS-CoV-2 virus. Clover's COVID-19 vaccine candidate is the combination of SCB-2019 and two adjuvants,Dynavax's CpG 1018 advanced adjuvant and aluminum hydroxide (alum).

Clover is currently advancing SPECTRA,a global pivotal Phase 2/3 clinical trial evaluating the efficacy,safety,and immunogenicity of SCB-2019 (CpG 1018/Alum),and expects interim data for vaccine efficacy around the middle of 2021. Pending positive interim data,Clover plans to submit conditional regulatory approval applications to the EMA,the NMPA and the WHO in the second half of 2021,and plans to commence product launch by the end of 2021.

About Clover Biopharmaceuticals

Clover Biopharmaceuticalsisa global clinical-stage biotechnology company committed to developing novelvaccines and biologic therapeutic candidates to address the world's most life-threateningdiseases and public health threats. The Trimer-Tag© technology platform is a product development platform for the creation of novel vaccines and biologictherapies. We have leveraged the Trimer-Tag© technology platform to become a COVID-19vaccine developer and potentially one of the first companies to commercialize a protein-basedCOVID-19 vaccine globally through the COVAX Facility. For more information,please visit our website: www.cloverbiopharma.com and follow the company onLinkedIn.

Clover Forward-looking Statements

This press release contains certain forward-looking statements and information relating to us and our subsidiaries that are based on the beliefs of our management as well as assumptions made by and information currently available to our management. When used in this [document],the words "aim," "anticipate," "believe," "could," "estimate," "expect," "going forward," "intend," "may," "might," "ought to," "plan," "potential," "predict," "project," "seek," "should," "will," "would" and the negative of these words and other similar expressions,as they relate to us or our management,are intended to identify forward-looking statements.

Forward-looking statements are based on our current expectations and assumptions regarding our business,the economy and other future conditions. We give no assurance that these expectations and assumptions will prove to have been correct. Because forward-looking statements relate to the future,they are subject to inherent uncertainties,risks and changes in circumstances that are difficult to predict. Our results may differ materially from those contemplated by the forward-looking statements. They are neither statements of historical fact nor guarantees or assurances of future performance. We caution you therefore against placing undue reliance on any of these forward-looking statements. Any forward-looking statement made by us in this document speaks only as of the date on which it is made. Factors or events that could cause our actual results to differ may emerge from time to time,and it is not possible for us to predict all of them. Subject to the requirements of applicable laws,rules and regulations,we undertake no obligation to update any forward-looking statement,whether as a result of new information,future events or otherwise. All forward-looking statements contained in this document are qualified by reference to this cautionary statement.

About CpG 1018

CpG 1018 is the adjuvant used in HEPLISAV-B® [Hepatitis B Vaccine (Recombinant),Adjuvanted],an adult hepatitis B vaccine approved by the U.S. Food and Drug Administration (FDA) and the European Commission. Dynavax developed CpG 1018 to provide an increased vaccine immune response,which has been demonstrated in HEPLISAV-B. CpG 1018 provides a well-developed technology and a significant safety database,potentially accelerating the development and large-scale manufacturing of a COVID-19 vaccine.

About Dynavax

Dynavax is a commercial stage biopharmaceutical company developing and commercializing novel vaccines. The Company's first commercial product,HEPLISAV-B® [Hepatitis B Vaccine (Recombinant),is approved in the U.S. and Europe for prevention of infection caused by all known subtypes of hepatitis B virus in adults age 18 years and older. Dynavax is also advancing CpG 1018 as a premier vaccine adjuvant through research collaborations and partnerships. Current collaborations are focused on adjuvanted vaccines for COVID-19,pertussis and universal influenza. For more information,visit www.dynavax.com and follow the company on LinkedIn.

Dynavax Forward-Looking Statements

This press release contains "forward-looking" statements,including statements regarding the potential to develop a COVID-19 vaccine containing CpG 1018,the timing and amount of potential sales to Clover and the timing of regulatory approvals. Actual results may differ materially from those set forth in this press release due to the risks and uncertainties inherent in vaccine research and development,including the timing of initiating clinical trials and completing development,whether CpG 1018 plus aluminum combined with Clover's protein subunit vaccine will prove to be beneficial in clinical trials,whether and when the vaccine will be approved for use,whether CEPI will continue to fund the Clover program through development and licensure,whether or how much Gavi or other commercial customers purchase from Clover,and whether sufficient quantities of CpG 1018 will be able to be manufactured,as well as other risks detailed in the "Risk Factors" section of our Annual Report on Form 10-K for the fiscal year ended December 31,2020,as well as discussions of potential risks,uncertainties and other important factors in our other filings with the U.S. Securities and Exchange Commission. We undertake no obligation to revise or update information herein to reflect events or circumstances in the future,even if new information becomes available. Information on Dynavax's website at www.dynavax.com is not incorporated by reference in our current periodic reports with the SEC.

Clover Biopharmaceuticals:

Cindy Min

Vice President,Public Affairs

media@cloverbiopharma.com

Naomi Eichenbaum

Vice President,Investor Relations

investors@cloverbiopharma.com

Dynavax Contacts:

Nicole Arndt

Senior Manager Investor Relations

narndt@dynavax.com

510-665-7264

Derek Cole

President,Investor Relations Advisory Solutions

derek.cole@IRadvisory.com