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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-06-17</periodOfReport>

    <issuer>
        <issuerCik>0001841387</issuerCik>
        <issuerName>Candel Therapeutics, Inc.</issuerName>
        <issuerTradingSymbol>CADL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001691160</rptOwnerCik>
            <rptOwnerName>Benz Edward J. JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CANDEL THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>117 KENDRICK ST., SUITE 450</rptOwnerStreet2>
            <rptOwnerCity>NEEDHAM</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02494</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.94</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-06-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>14240</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2035-06-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>14240</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14240</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This option is subject to time-based vesting. The shares underlying this option shall vest and become exercisable upon the earlier of (i) June 17, 2026 or (ii) the date of the next Annual Meeting of Stockholders of the Issuer; provided, however, that all vesting shall cease if the Reporting Person resigns from the Board of Directors (the &quot;Board&quot;) of the Issuer or otherwise ceases to serve as a director, unless the Board determines that the circumstances warrant continuation of vesting.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Charles Schoch, as Attorney-In-Fact for Edward J. Benz Jr.</signatureName>
        <signatureDate>2025-06-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
