Company: DVAX
Filing Date: 2025-04-17
Form Type: PRRN14A
Source: 0001193125-25-084044
Chunk: 5

Company: DYNAVAX TECHNOLOGIES CORP
Filing Date: 2025-04-17
Form: PRRN14A
Chunk 5
---
-paid envelope provided. |

| • |     | If your shares of Common Stock are held in a brokerage account, you are considered the beneficial owner of the                                                                                                                                  
 shares of Common Stock, and these proxy materials, together with a WHITE voting instruction form, are being forwarded to you by your broker. As a beneficial owner, if you wish to vote, you must instruct your broker how to vote. Your broker 
 cannot vote your shares of Common Stock on your behalf without your instructions.                                                                                                                                                               |

| • |     | Depending upon your broker, you may be able to vote either by toll-free telephone or by the Internet. Please                                                                                                                            
 refer to the enclosed WHITE voting instruction form for instructions on how to vote electronically. You may also vote by marking, signing, dating and returning the enclosed WHITE voting instruction form in the postage-paid envelope 
 provided.                                                                                                                                                                                                                               |

As we are using a “universal” proxy card containing both of the Deep Track Nominees as well as the Company’s nominees, there is no need to vote using a gold proxy card regardless of how you intend to vote. The Deep Track Parties strongly urge you NOT to sign or return any gold proxy cards or gold voting instruction forms that you may receive from Dynavax. If you return the gold management proxy card marked “withhold” as a protest against the incumbent directors, it will revoke any WHITE proxy card you may have previously voted. If you have any questions, require assistance in voting your WHITE proxy card, or need additional copies of Deep Track’s proxy materials, please contact our proxy solicitor, Innisfree M&A Incorporated (“Innisfree”), using the contact information provided here: Innisfree M&A Incorporated. 501 Madison Avenue, 20 thFloor New York, New York 10022 Stockholders call toll-free (877) 687-1865 Banks and Brokers call: (212) 750-5833 4

BACKGROUND OF THE SOLICITATION The following is a chronology of events leading up to this proxy solicitation:

| • |     | Senior members of Deep Track Capital first purchased Dynavax Common Stock in 2010 at a prior investment firm, as                                                                                                     
 part of a financing to assist the Company in further advancing the development of Heplisav. Since that time, they have closely followed the progress of Heplisav through clinical development and commercialization. |

| • |     | The Deep Track Fund, advised by Deep Track Capital, invested in the Company beginning in Q4 202