Cerus (CERS) POSASR Automatic shelf registration (post-effective amendment)

Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the reference to our firm under the caption “Experts” in Amendment No. 1 to the Registration Statement (Form S-3 No. 333-251302), related base prospectus and at the market offering prospectus of Cerus Corporation for the registration of common stock, preferred stock, debt securities and warrants and to the incorporation by reference therein of our reports dated February 22, 2022, with respect to the consolidated financial statements of Cerus Corporation, and the effectiveness of internal control over financial reporting of Cerus Corporation, included in its Annual Report (Form 10-K) for the year ended December 31, 2021, filed with the Securities and Exchange Commission.

/s/ Ernst & Young LLP

San Mateo, California

March 1, 2023