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): October 29, 2026

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.)

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):

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

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 7.01. Regulation FD Information.

On October 29, 2026, Novavax, Inc. (“Novavax” or the “Company”) issued a press release announcing the information discussed under Item 8.01 hereof. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

The information contained in this Item 7.01 shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 8.01. Other Events.

On October 28, 2026 Sanofi Pasteur Inc. (“Sanofi”) dosed the fifth patient in its Phase 3 influenza-COVID-19 combination vaccine trial in the European Union, utilizing the Company’s COVID-19 component. Dosing of the fifth patient has triggered a $125 million milestone payment from Sanofi under the Company’s Collaboration and License Agreement with Sanofi. The Company anticipates receipt of payment by the first quarter of 2027.

Cautionary Note Regarding Forward-Looking Statements.

This Current Report on Form 8-K contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. We intend such forward-looking statements to be covered by the safe harbor provisions for forward-looking statements contained in Section 27A of the Securities Act of 1933, as amended (the “Securities Act”) and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Any statements in the discussion below and elsewhere in this Current Report about expectations, beliefs, plans, objectives, assumptions, or future events or performance of the Company are not historical facts and are forward-looking statements. Such forward-looking statements include, without limitation, statements regarding expected milestone payments under the Sanofi agreement. Generally, forward-looking statements can be identified through the use of words or phrases such as “believe,” “may,” “could,” “will,” “would,” “possible,” “can,” “estimate,” “continue,” “ongoing,” “consider,” “anticipate,” “intend,” “seek,” “plan,” “project,” “expect,” “should,” “would,” “aim,” or “assume,” the negative of these terms, or other comparable terminology, although not all forward-looking statements contain these words.

Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based only on Novavax’s current beliefs and expectations about the future of our business, events and trends, and other future conditions. Forward-looking statements involve estimates, assumptions, risks, and uncertainties that could cause actual results or outcomes to differ materially from those expressed or implied in any forward-looking statements, and, therefore, you should not place considerable reliance on any such forward-looking statements. Such risks and uncertainties include, without limitation, challenges related to Novavax's partnership with Sanofi, and in pursuing additional partnership opportunities; challenges satisfying, alone or together with partners, various safety, efficacy, and product characterization requirements, challenges or delays in conducting clinical trials or studies for its product candidates; manufacturing, distribution or export delays or challenges; Novavax's substantial dependence on Serum Institute of India Pvt. Ltd. and Serum Life Sciences Limited for co-formulation and filling Novavax's COVID-19 vaccine and the impact of any delays or disruptions in their operations; the impact of potential legislative, regulatory, or policy changes under the current presidential administration, including any adverse impact funding for vaccine research and development, reimbursement for vaccines and their administration, vaccine mandates and recommendations, and public perception of vaccine importance; uncertainty with respect to pricing, third-party reimbursement and healthcare reform; the impact of any new or changes in interpretations of existing trade measures, including tariffs, embargoes, sanctions, import restrictions, and export licensing requirements; difficulty obtaining scarce raw materials and supplies including for its proprietary adjuvant; resource constraints, including human capital and manufacturing capacity; constraints on Novavax's ability to pursue planned regulatory pathways, alone or with partners, in multiple jurisdictions simultaneously, leading to staggering of regulatory filings, and potential regulatory actions; Novavax's ability to timely deliver doses; challenges in obtaining commercial adoption and market acceptance of its COVID-19 vaccine or any COVID-19 variant strain containing formulation, or for its CIC vaccine candidates, stand-alone influenza vaccine candidates or other candidates; challenges meeting contractual requirements under agreements with multiple commercial, governmental, and other entities, including requirements to deliver doses that may require Novavax to refund portions of upfront and other payments previously received or result in reduced future payments pursuant to such agreements; challenges related to the seasonality of vaccinations against COVID-19; challenges related to the demand for vaccinations against COVID-19 or influenza; challenges in identifying and successfully pursuing innovation expansion opportunities; Novavax's expectations as to expenses and cash needs may prove not to be correct for reasons such as changes in plans or actual events being different than its assumptions; and other risks and uncertainties identified in Part I, Item 1A “Risk Factors” of our Annual Report on Form 10-K for the year ended December 31, 2025, filed with the Securities and Exchange Commission (“SEC”) on February 26, 2026, as updated by the information in Part II, Item 1A “Risk Factors” in our subsequent Quarterly Reports on Form 10-Q which may be further detailed and modified or updated in other documents we file with the SEC from time to time, and are available at www.sec.gov and at www.novavax.com. You are encouraged to read these filings as they are made.

Novavax cannot guarantee future results, events, level of activity, performance, or achievement. Any or all of Novavax’s forward-looking statements in this Current Report on Form 8-K may turn out to be inaccurate or materially different from actual results. Further, any forward-looking statement speaks only as of the date when it is made, and Novavax undertakes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise, unless required by law. New factors emerge from time to time, and it is not possible for Novavax to predict which factors will arise. In addition, Novavax cannot assess the impact of each factor on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements.

Item 9.01. Financial Statements and Exhibits.

(d) 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.