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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 fBZP9u/g2dvYKQ/Vggi3yw==

<SEC-DOCUMENT>0001170961-08-000003.txt : 20080310
<SEC-HEADER>0001170961-08-000003.hdr.sgml : 20080310
<ACCEPTANCE-DATETIME>20080310153901
ACCESSION NUMBER:		0001170961-08-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080306
FILED AS OF DATE:		20080310
DATE AS OF CHANGE:		20080310

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NOVAVAX INC
		CENTRAL INDEX KEY:			0001000694
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				222816046
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		9920 BELWARD CAMPUS DRIVE
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20850
		BUSINESS PHONE:		240-268-2000

	MAIL ADDRESS:	
		STREET 1:		9920 BELWARD CAMPUS DRIVE
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20850

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Robinson Jim
		CENTRAL INDEX KEY:			0001409295

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26770
		FILM NUMBER:		08677716

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		240-268-2000

	MAIL ADDRESS:	
		STREET 1:		9950 BELWARD CAMPUS DRIVE
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20850
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-03-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001000694</issuerCik>
        <issuerName>NOVAVAX INC</issuerName>
        <issuerTradingSymbol>nvax</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001409295</rptOwnerCik>
            <rptOwnerName>Robinson Jim</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>9950 BELWARD CAMPUS DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ROCKVILLE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>20850</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP of Tech. &amp; Qual. Operations</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option - right to buy</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.61</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-03-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>37500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2018-03-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>37500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>37500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The options vest in three equal annual installments beginning on March 6, 2009.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Len Stigliano, as attorney-in-fact for Jim Robinson</signatureName>
        <signatureDate>2008-03-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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