Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement on Form S-3 of AVANT Immunotherapeutics, Inc. of our report dated March 16, 2007 relating to the financial statements, management’s assessment of the effectiveness of internal control over financial reporting and the effectiveness of internal control over financial reporting, which appears in AVANT Immunotherapeutics, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2006. We also consent to the reference to us under the heading “Experts” in such Registration Statement.

/s/ PRICEWATERHOUSECOOPERS LLP

PricewaterhouseCoopers LLP
Boston, Massachusetts
May 21, 2007