<SEC-DOCUMENT>0000899243-21-030480.txt : 20210728
<SEC-HEADER>0000899243-21-030480.hdr.sgml : 20210728
<ACCEPTANCE-DATETIME>20210728203204
ACCESSION NUMBER:		0000899243-21-030480
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210728
FILED AS OF DATE:		20210728
DATE AS OF CHANGE:		20210728

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Sanofi
		CENTRAL INDEX KEY:			0001121404
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		STATE OF INCORPORATION:			I0
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-40655
		FILM NUMBER:		211124396

	BUSINESS ADDRESS:	
		STREET 1:		54 RUE LA BOETIE
		CITY:			PARIS
		STATE:			I0
		ZIP:			75008
		BUSINESS PHONE:		33153774400

	MAIL ADDRESS:	
		STREET 1:		54 RUE LA BOETIE
		CITY:			PARIS
		STATE:			I0
		ZIP:			75008

	FORMER NAME:	
		FORMER CONFORMED NAME:	SANOFI-AVENTIS
		DATE OF NAME CHANGE:	20040826

	FORMER NAME:	
		FORMER CONFORMED NAME:	SANOFI SYNTHELABO SA
		DATE OF NAME CHANGE:	20010104

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Icosavax, Inc.
		CENTRAL INDEX KEY:			0001786255
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1616 EASTLAKE AVE E, SUITE 208
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98102
		BUSINESS PHONE:		(858) 775-4523

	MAIL ADDRESS:	
		STREET 1:		1616 EASTLAKE AVE E, SUITE 208
		CITY:			SEATTLE
		STATE:			WA
		ZIP:			98102
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>doc3.xml
<DESCRIPTION>FORM 3 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2021-07-28</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001786255</issuerCik>
        <issuerName>Icosavax, Inc.</issuerName>
        <issuerTradingSymbol>ICVX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001121404</rptOwnerCik>
            <rptOwnerName>Sanofi</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>54, RUE LA BOETIE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PARIS</rptOwnerCity>
            <rptOwnerState>I0</rptOwnerState>
            <rptOwnerZipCode>75008</rptOwnerZipCode>
            <rptOwnerStateDescription>FRANCE</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series A-1 Preferred Stock (par value, $0.0001)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3003224</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Through its wholly-owned subsidiary, Aventis, Inc.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series B-1 Preferred Stock (par value, $0.0001)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>85278</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Through its wholly-owned subsidiary, Aventis, Inc.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The shares of Series A-1 Preferred Stock and Series B-1 Preferred Stock are convertible, at any time at the holder's election, to shares of the Issuer's Common Stock, as shown in Column 3, at a ratio of 4.1557-for-1. In addition, effective immediately prior to the closing of the Issuer's initial public offering of its Common Stock, each share of Series A-1 Preferred Stock and Series B-1 Preferred Stock will automatically convert to shares of the Issuer's Common Stock at a ratio of 4.1557-for-1 as shown in Column 3. The Series A-1 Preferred Stock and Series B-1 Preferred Stock have no expiration date.</footnote>
        <footnote id="F2">Sanofi is the beneficial owner of 3,003,224 Shares of Series A-1 Preferred Stock and 85,278 Shares of Series B-1 Preferred Stock of the Issuer through its wholly owned subsidiary, Aventis, Inc.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Alexander Roger, Head of Securities Law and Capital Markets</signatureName>
        <signatureDate>2021-07-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
