<SEC-DOCUMENT>0000899243-21-004755.txt : 20210203
<SEC-HEADER>0000899243-21-004755.hdr.sgml : 20210203
<ACCEPTANCE-DATETIME>20210203190031
ACCESSION NUMBER:		0000899243-21-004755
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210131
FILED AS OF DATE:		20210203
DATE AS OF CHANGE:		20210203

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Brown William Michael
		CENTRAL INDEX KEY:			0001742241

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32587
		FILM NUMBER:		21588013

	MAIL ADDRESS:	
		STREET 1:		910 CLOPPER ROAD
		STREET 2:		SUITE 201S
		CITY:			GAITHERSBURG
		STATE:			MD
		ZIP:			20878

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Altimmune, Inc.
		CENTRAL INDEX KEY:			0001326190
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				202726770
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		910 CLOPPER ROAD
		STREET 2:		SUITE 201S
		CITY:			GAITHERSBURG
		STATE:			MD
		ZIP:			20878
		BUSINESS PHONE:		2406541450

	MAIL ADDRESS:	
		STREET 1:		910 CLOPPER ROAD
		STREET 2:		SUITE 201S
		CITY:			GAITHERSBURG
		STATE:			MD
		ZIP:			20878

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PHARMATHENE, INC
		DATE OF NAME CHANGE:	20071016

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	HEALTHCARE ACQUISITION CORP
		DATE OF NAME CHANGE:	20050505
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-01-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001326190</issuerCik>
        <issuerName>Altimmune, Inc.</issuerName>
        <issuerTradingSymbol>ALT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001742241</rptOwnerCik>
            <rptOwnerName>Brown William Michael</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ALTIMMUNE, INC., 910 CLOPPER ROAD,</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 201S</rptOwnerStreet2>
            <rptOwnerCity>GAITHERSBURG</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>20878</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.0001</value>
            </securityTitle>
            <transactionDate>
                <value>2021-01-31</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>937</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.14</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16918</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (option to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>16.71</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-02-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>90000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2031-02-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $0.0001</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>90000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>90000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F4"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-02-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>24664</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $0.0001</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>24664</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24664</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These shares were purchased due to participation by the reporting individual in the issuer's 2019 Employee Stock Purchase Plan (&quot;ESPP&quot;). It pertains to the ESPP purchase period from August 1, 2020 through January 31, 2021.</footnote>
        <footnote id="F2">In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the issuer's common stock on January 31, 2021.</footnote>
        <footnote id="F3">Twenty-five percent of the shares underlying the option become vested and exercisable on February 1, 2022 and the remaining 75% of the shares underlying the option become vested and exercisable in substantially equal monthly installments over the 36 months following February 2, 2022, subject to the reporting person's continued service through the applicable vesting date.</footnote>
        <footnote id="F4">Each Restricted Stock Unit (&quot;RSU&quot;) represents a contingent right to receive one share of Common Stock, par value $0.0001, when vested.</footnote>
        <footnote id="F5">The RSUs become vested and exercisable in substantially equal annual installments over the 4 years following February 2, 2021, subject to the reporting person's continued service through the applicable vesting date, and have no expiration date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ William Brown</signatureName>
        <signatureDate>2021-02-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
