<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-02-10</periodOfReport>

    <notSubjectToSection16>true</notSubjectToSection16>

    <issuer>
        <issuerCik>0001029142</issuerCik>
        <issuerName>DYNAVAX TECHNOLOGIES CORP</issuerName>
        <issuerTradingSymbol>DVAX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002015536</rptOwnerCik>
            <rptOwnerName>Deep Track Biotechnology Master Fund, Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WALKERS CORPORATE LIMITED</rptOwnerStreet1>
            <rptOwnerStreet2>190 ELGIN AVE</rptOwnerStreet2>
            <rptOwnerCity>GEORGE TOWN</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode>KY1-9001</rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>true</isTenPercentOwner>
            <isOther>false</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001856083</rptOwnerCik>
            <rptOwnerName>Deep Track Capital, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 GREENWICH AVENUE, 3RD FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>true</isTenPercentOwner>
            <isOther>false</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001397513</rptOwnerCik>
            <rptOwnerName>KROIN DAVID</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DEEP TRACK CAPITAL, LP,</rptOwnerStreet1>
            <rptOwnerStreet2>200 GREENWICH AVENUE, 3RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>true</isTenPercentOwner>
            <isOther>false</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2026-02-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>U</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>15726349</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This Form 4 reports securities transacted pursuant to the Agreement and Plan of Merger (the &quot;Merger Agreement&quot;) by and among the Issuer, SANOFI, a French societe anonyme (&quot;Parent&quot;), and Samba Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Parent (&quot;Purchaser&quot;).  Pursuant to the Merger Agreement, Purchaser completed a tender offer to acquire all of the issued and outstanding shares of common stock of the Issuer, par value $0.001 per share (the &quot;Common Stock&quot;), for $15.50 per share (the &quot;Offer Price&quot;), in cash, without interest and subject to any applicable withholding of taxes. On February 10, 2026, Purchaser merged with and into the Issuer, with the Issuer surviving as an indirect wholly owned subsidiary of Parent (the effective time of such merger, the &quot;Effective Time&quot;). Pursuant to the terms of the Merger Agreement, at the Effective Time, each share of Common Stock held by the Reporting Persons were tendered in exchange for the Offer Price.</footnote>
        <footnote id="F2">Represents securities held by Deep Track Biotechnology Master Fund, Ltd. Deep Track Capital, LP is the investment manager of Deep Track Biotechnology Master Fund, Ltd. Mr. David Kroin is the managing member of Deep Track Capital GP, LLC, the general partner of Deep Track Capital, LP, and by virtue of such status may be deemed to be the beneficial owner of the shares owned by Deep Track Biotechnology Master Fund, Ltd. Deep Track Capital, LP and Mr. Kroin disclaim beneficial ownership of such shares except to the extent of their respective pecuniary interests.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Deep Track Biotechology Master Fund, Ltd. /s/ David Kroin, Director</signatureName>
        <signatureDate>2026-02-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Deep Track Capital, LP /s/ David Kroin, Managing Member of the General Partner of the Investment Adviser</signatureName>
        <signatureDate>2026-02-11</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ David Kroin</signatureName>
        <signatureDate>2026-02-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
