EXHIBIT 23.1
Consent of Independent Registered Public Accounting Firm
We consent to the reference to our firm under the caption Experts in the Registration
Statement (Form S-3, No.333-00000) and related Prospectus of Novavax, Inc. for the registration of
its common stock, preferred stock and warrants, with an aggregate public offering price not to
exceed $100,000,000 (on a consolidated basis). We also consent to the incorporation by reference
therein of our reports dated March 11, 2005, with respect to the consolidated financial statements
of Novavax, Inc., Novavax, Inc. managements assessment of the effectiveness of internal control
over financial reporting, and the effectiveness of internal control over financial reporting of
Novavax, Inc., included in its Annual Report (Form 10-K/A) for the year ended December 31, 2004,
filed with the Securities and Exchange Commission.
/s/ Ernst & Young LLP
Philadelphia, Pennsylvania
December 19, 2005