X0306 4 2021-02-01 0 0001029142 DYNAVAX TECHNOLOGIES CORP DVAX 0001580849 Janssen Robert C/O DYNAVAX TECHNOLOGIES 2100 POWELL STREET, SUITE 900 EMERYVILLE CA 94608 0 1 0 0 Senior Vice President Common Stock 2021-02-01 4 S 0 42155 10.64 D 86485 D The sales reported on this Form 4 were effected pursuant to a 10b5-1 trading plan adopted on August 11,2020. This transaction was executed in multiple trades at prices ranging from $9.93 to $11.64; the price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide full information regarding the number of shares and prices at which the transactions were effected upon request to the SEC staff, Dynavax, or a security holder of Dynavax. Includes 1,374 shares acquired under Issuer's 2014 Employee Stock Purchase Plan (ESPP) on August 14, 2020. /s/ Robert Janssen 2021-02-03