Exhibit 5.1


  200 Clarendon Street
  Boston, Massachusetts 02116



Tel: +1.617.948.6000 Fax: +1.617.948.6001


  Austin   Moscow
  Beijing   Munich
  Boston   New York
  Brussels   Orange County
  Century City   Paris
  Chicago   Riyadh
  Dubai   San Diego
December 8, 2021   Düsseldorf   San Francisco
  Frankfurt   Seoul
  Hamburg   Shanghai
  Hong Kong   Silicon Valley
  Houston   Singapore
  London   Tel Aviv
ContraFect Corporation   Los Angeles   Tokyo
28 Wells Avenue, Third Floor   Madrid   Washington, D.C.
Yonkers, New York 10701   Milan  

Re:    Registration Statement on Form S-3

To the addressee set forth above:

We have acted as special counsel to ContraFect Corporation, a Delaware corporation (the “Company”), in connection with its filing on the date hereof with the Securities and Exchange Commission (the “Commission”) of a registration statement on Form S-3 (as amended, the “Registration Statement”), including a prospectus (the “Prospectus”), under the Securities Act of 1933, as amended (the “Act”), relating to the registration for issue and sale by the Company of 8,819,904 shares (the “Shares”) of common stock, par value $0.0001 per share, of the Company (the “Common Stock”) upon the exercise from time to time of warrants to purchase shares of Common Stock (the “Warrants”). This opinion is being furnished in connection with the requirements of Item 601(b)(5) of Regulation S-K under the Act, and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statement or the Prospectus, other than as expressly stated herein with respect to the issue of the Shares.

As such counsel, we have examined such matters of fact and questions of law as we have considered appropriate for purposes of this letter. With your consent, we have relied upon certificates and other assurances of officers of the Company and others as to factual matters without having independently verified such factual matters. We are opining herein as to the General Corporation Law of the State of Delaware (the “DGCL”), and we express no opinion with respect to any other laws, or as to any matters of municipal law or the laws of any local agencies within any state.

Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof, when the Shares shall have been duly registered on the books of the transfer agent and registrar therefor in the name or on behalf of the Warrant holders, and have been issued by the Company against payment therefor (not less than par value) in the circumstances contemplated by the Warrants, the issue of the Shares will have been duly authorized by all

December 8, 2021

Page 2




necessary corporate action of the Company, and the Shares will have been validly reserved by all necessary corporate action of the Company, and the Shares will be validly issued, fully paid and nonassessable. In rendering the foregoing opinion, we have assumed that (i) the Company will comply with all applicable notice requirements regarding uncertificated shares provided in the DGCL and (ii) upon the issue of any of the Shares, the total number of shares of Common Stock issued and outstanding will not exceed the total number of shares of Common Stock that the Company is then authorized to issue under its certificate of incorporation and by the board of directors of the Company in connection with the offering contemplated by the Registration Statement.

This opinion is for your benefit in connection with the Registration Statement and may be relied upon by you and by persons entitled to rely upon it pursuant to the applicable provisions of the Act. We consent to your filing this opinion as an exhibit to the Registration Statement and to the reference of our firm contained in the Prospectus under the heading “Legal Matters.” We further consent to the incorporation by reference of this letter and consent into any registration statement or post-effective amendment to the Registration Statement filed pursuant to Rule 462(b) under the Act with respect to the Shares. In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission thereunder.