UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): January 21, 2020

NOVAVAX, INC.

(Exact name of registrant as specified in charter)

21 Firstfield Road

Gaithersburg, Maryland 20878

(Address of Principal Executive Offices, including Zip Code)

(240) 268-2000

(Registrant’s telephone number, including area code)

(Former name or former address, if changed since last report.)

Securities registered pursuant to Section 12(b) of the Act:

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 8.01. Other Events.

On January 21, 2020, Novavax, Inc. (the “Company”), filed a prospectus supplement with the Securities and Exchange Commission which contemplates the sale of up to $100,000,000 of shares of the Company’s common stock (the “Shares”) from time to time in at-the-market offerings pursuant to an At Market Issuance Sales Agreement with B. Riley FBR, Inc. (the “Sales Agent”), dated as of January 21, 2020 (the “2020 Sales Agreement”). Sales pursuant to the 2020 Sales Agreement will be made only upon instructions by the Company to the Sales Agent, and the Company cannot provide any assurances that it will issue any Shares pursuant to the 2020 Sales Agreement.

A copy of the 2020 Sales Agreement is attached as Exhibit 1.1 hereto and is incorporated herein by reference. The foregoing description of the material terms of the 2020 Sales Agreement does not purport to be complete and is qualified in its entirety by reference to such agreements.

Ropes & Gray LLP, counsel to the Company, has issued a legal opinion relating to the Shares. A copy of such legal opinion, including the consent included therein, is attached as Exhibit 5.1 hereto.

Item 9.01. Financial Statements and Exhibits.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.