EXHIBIT 5.1 Emergent BioSolutions Inc. 400 Professional Drive, Suite 400 Gaithersburg, MD 20879 T 240-631-3200 August 9, 2021 Re: Registration Statement on Form S-3 Ladies and Gentlemen: I am Associate General Counsel and Assistant Corporate Secretary of Emergent BioSolutions Inc., a Delaware corporation (the “Company”). This opinion is furnished to you in connection with a Registration Statement on Form S-3 (the “Registration Statement”) to be filed by the Company, with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Securities Act”), for the registration of the following securities of the Company (the “Securities”): (i) senior debt securities (the “Senior Debt Securities”); (ii) subordinated debt securities (the “Subordinated Debt Securities” and, together with the Senior Debt Securities, the “Debt Securities”); (iii) common stock, par value $0.001 per share (the “Common Stock”); (iv) preferred stock, par value $0.001 per share (the “Preferred Stock”); (v) depositary shares representing a fractional interest in or multiple shares of Preferred Stock (the “Depositary Shares”); (vi) units of the Corporation (the “Units”); and (vii) warrants to purchase Debt Securities, Common Stock, Preferred Stock or Depositary Shares (the “Warrants”); all of which may be issued from time to time on a delayed or continuous basis pursuant to Rule 415 under the Securities Act at an indeterminate aggregate offering price as set forth in the Registration Statement, the base prospectus contained therein (the “Prospectus”) and any amendments or supplements thereto. The Senior Debt Securities may be issued pursuant to a senior indenture (together with any supplemental indentures relating to the Senior Debt Securities, the “Senior Indenture”) to be entered into between the Company and a trustee to be named in the Senior Indenture and duly qualified under the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”). The Subordinated Debt Securities may be issued pursuant to a subordinated indenture (together with any supplemental indentures relating to the Subordinated Debt Securities, the “Subordinated Indenture,” and together with the Senior Indenture, the “Indentures”) to be entered into between the Company and a trustee to be named in the Subordinated Indenture and duly qualified under the Trust Indenture Act. The preferences, limitations and relative rights of shares of any series of Preferred Stock will be set forth in a Certificate of Designation (a “Certificate of Designation”) with respect thereto.
2 The shares of Preferred Stock represented by Depositary Shares will be deposited pursuant to a Depositary Agreement (the “Depositary Agreement”) to be entered into between the Company and a bank or trust company to be named as depositary, and the preferences, limitations and relative rights of such shares of Preferred Stock will be set forth in a Certificate of Designation with respect thereto. The Units may be issued pursuant to a Unit Agreement (the “Unit Agreement”) to be entered into between the Company and a bank or trust company to be named as unit agent. The Warrants may be issued pursuant to a warrant agreement (the “Warrant Agreement”) to be entered into between the Company and a bank or trust company to be named as warrant agent. This opinion is being delivered pursuant to the requirements of Item 601(b)(5) of Regulation S-K under the Securities Act. In rendering the opinion set forth herein, I or attorneys under my supervision (with whom I have consulted) have examined the Registration Statement (including the exhibits thereto) and originals or copies, certified or otherwise identified to our satisfaction, of such records of the Company and such agreements, certificates and receipts of public officials, certificates of officers or other representatives of the Company and others, and such other documents as I or attorneys under my supervision (with whom I have consulted) have deemed necessary or appropriate as a basis for the opinion set forth below. In my examination, I or attorneys under my supervision (with whom I have consulted) have assumed the legal capacity of all natural persons, the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to original documents of all documents submitted to us as facsimile, electronic, certified or photostatic copies, and the authenticity of the originals of such copies. As to any facts material to this opinion that I or attorneys under my supervision (with whom I have consulted) did not independently establish or verify, I have relied upon statements and representations of officers and other representatives of the Company and others and of public officials. I have assumed that (i) the Registration Statement will be effective and will comply with all applicable laws at the time Securities are offered or issued as contemplated by the Registration Statement; (ii) one or more prospectus supplements will have been prepared and filed with the Commission describing the Securities offered thereby; (iii) all Securities will be issued and sold in compliance with applicable federal and state securities laws and in the manner stated in the Registration Statement, the Prospectus and any applicable prospectus supplement; (iv) in the case of Debt Securities, (a) the applicable Indenture will be duly authorized, executed and delivered by the trustee named therein in substantially the form filed as Exhibit 4.2 or Exhibit 4.3 to the Registration Statement, (b) the applicable Indenture will be duly qualified under the Trust Indenture Act, and the applicable trustee will be duly eligible to serve as trustee, and (c) the Debt Securities will be duly authenticated by the trustee named in the applicable Indenture; (v) any Depositary Agreement, Unit Agreement or Warrant Agreement, as applicable, will be duly authorized, executed and delivered by all parties thereto other than the Company; (vi) a definitive purchase, underwriting or similar agreement with respect to any Securities offered will be duly authorized, executed and delivered by all parties
3 thereto other than the Company; (vii) any Securities issuable upon conversion, exchange or exercise of any Security being offered will be duly authorized, created and, if appropriate, reserved for issuance upon such conversion, exchange or exercise; (viii) with respect to shares of Common Stock or Preferred Stock offered, there will be sufficient shares of Common Stock or Preferred Stock authorized under the Certificate of Incorporation and not otherwise reserved for issuance; (ix) at the time of the issuance and sale of the Securities, the Company will be validly existing as a corporation and in good standing under the laws of the State of Delaware; and (x) any Unit Agreement or Warrant Agreement will be governed by the laws of the State of New York or the General Corporation Law of the State of Delaware. I have also assumed that there will not have occurred, prior to the date of issuance of the Securities, any change in law affecting the validity or enforceability of such Securities and that at the time of the issuance and sale of such Securities, the Board of Directors of the Company (or any committee of the Board of Directors or any person acting pursuant to authority properly delegated to such person by the Board of Directors or any committee of the Board of Directors) shall not have taken any action to rescind or otherwise reduce its prior authorization of the issuance of such Securities. My opinions below are qualified to the extent that they may be subject to or affected by (i) applicable bankruptcy, insolvency, reorganization, moratorium, usury, fraudulent conveyance or similar laws relating to or affecting the rights or remedies of creditors generally, (ii) duties and standards imposed on creditors and parties to contracts, including, without limitation, requirements of materiality, good faith, reasonableness and fair dealing, (iii) general equitable principles, and (iv) acceleration of the Debt Securities which may affect the collectability of that portion of the stated principal amount thereof that might be determined to constitute unearned interest thereon. Furthermore, I express no opinion as to the availability of any equitable or specific remedy upon any breach of any of the agreements as to which I am opining herein, or any of the agreements, documents or obligations referred to therein, or to the successful assertion of any equitable defenses, inasmuch as the availability of such remedies or the success of any equitable defenses may be subject to the discretion of a court. I also express no opinion herein as to the laws of any state or jurisdiction other than the state laws of the State of New York, the General Corporation Law of the State of Delaware and the federal laws of the United States of America. I also express no opinion herein with respect to compliance by the Company with the securities or “blue sky” laws of any state or other jurisdiction of the United States or of any foreign jurisdiction. In addition, I express no opinion and make no statement herein with respect to the antifraud laws of any jurisdiction. I also express no opinion herein as to any provision of any agreement (i) that may be deemed to or construed to waive any right of the Company, (ii) to the effect that rights and remedies are not exclusive, that every right or remedy is cumulative and may be exercised in addition to or with any other right or remedy and does not preclude recourse to one or more other rights or remedies, (iii) relating to the effect of invalidity or unenforceability of any provision of any agreement on the validity or enforceability of any other provision thereof, (iv) that is in violation of public policy, (v) relating to indemnification and contribution with respect to securities law matters, (vi) which provides that the terms of any agreement may not be waived or modified except in writing, (vii) purporting to indemnify any person against his, her or its own negligence or intentional misconduct, (viii) requiring the payment of penalties,
4 consequential damages or liquidated damages or (ix) relating to choice of law or consent to jurisdiction. Based upon and subject to the foregoing, I am of the opinion that: 1. With respect to the Debt Securities, when (i) specifically authorized for issuance by proper action of the Company’s Board of Directors or an authorized committee thereof (the “Authorizing Resolutions”), (ii) the applicable Indenture has been duly authorized, executed and delivered, (iii) the terms of the Debt Securities and of their issuance and sale have been duly established in conformity with the applicable Indenture and the Authorizing Resolutions and assuming such terms and sale do not violate any applicable law or result in a default under or breach of any agreement or instrument binding upon the Company and comply with any requirement or restriction imposed by any court or governmental body having jurisdiction over the Company, (iv) such Debt Securities have been duly executed by the Company and authenticated by the applicable trustee in accordance with the applicable Indenture and delivered and sold as contemplated by the Registration Statement, the Prospectus and any applicable prospectus supplement in accordance with the applicable underwriting or other purchase agreement against payment therefor, and (v) the Company has received the consideration provided for in the Authorizing Resolutions and the applicable underwriting agreement or other purchase agreement, such Debt Securities will constitute valid and binding obligations of the Company enforceable against the Company in accordance with their terms. 2. With respect to shares of Common Stock, when (i) specifically authorized for issuance by the Authorizing Resolutions, (ii) the terms of the issuance and sale of the Common Stock have been duly established in conformity with the Certificate of Incorporation, Bylaws and Authorizing Resolutions, (iii) the shares of Common Stock have been issued and delivered as contemplated by the Registration Statement, the Prospectus and any applicable prospectus supplement in accordance with the applicable underwriting or other purchase agreement or upon conversion or exercise of any Security offered under the Registration Statement against payment therefor, and (iv) the Company has received the consideration provided for in the Authorizing Resolutions and the applicable underwriting agreement or other purchase agreement and such consideration per share is not less than the par value per share of the Common Stock, the Common Stock will be validly issued, fully paid and nonassessable. 3. With respect to shares of any series of Preferred Stock, when (i) the Authorizing Resolutions have specifically authorized the issuance and terms of the shares of the series, the terms of the offering thereof and related matters, including resolutions establishing and designating the series and fixing and determining the preferences, limitations and relative rights thereof and the filing of a Certificate of Designation with respect to the series with the Secretary of State of the State of Delaware, and such Certificate of Designation has been duly filed, (ii) the terms of the issuance and sale of the series of Preferred Stock have been duly established in conformity with the Certificate of Incorporation, Bylaws and Authorizing Resolutions, (iii) the shares of the series of Preferred Stock have been issued and delivered as contemplated by the Registration Statement, the Prospectus and any applicable prospectus supplement in accordance with the applicable underwriting or other purchase agreement against payment therefor, and (iv) the Company has received the consideration provided for in the Authorizing Resolutions and the applicable
5 underwriting agreement or other purchase agreement and such consideration per share is not less than the par value per share of the Preferred Stock, the shares of such series of Preferred Stock will be validly issued, fully paid and nonassessable. 4. With respect to the Depositary Shares, when (i) the Authorizing Resolutions have specifically authorized the issuance and terms of the Depositary Shares, the terms of the offering thereof and related matters, including the adoption of a Certificate of Designation relating to the Preferred Stock underlying the Depositary Shares and the filing of the Certificate of Designation with the Secretary of State of the State of Delaware, and such Certificate of Designation has been duly filed, (ii) the applicable Depositary Agreement relating to the Depositary Shares has been duly authorized, executed and delivered; any depositary receipts evidencing rights in the Depositary Shares have been executed; and the depositary appointed by the Company, (iii) the terms of the issuance and sale of the Depositary Shares have been duly established in conformity with the Certificate of Incorporation and Bylaws, (iv) the Depositary Shares have been issued and delivered as contemplated by the Registration Statement, the Prospectus and any applicable prospectus supplement in accordance with the applicable underwriting or other purchase agreement against payment therefor, (v) the shares of Preferred Stock underlying the Depositary Shares have been deposited with a bank or trust company (which meets the requirements for the depositary set forth in the Registration Statement), and (vi) the Company has received the consideration provided for in the Authorizing Resolutions and the applicable underwriting agreement or other purchase agreement, the Depositary Shares will be legally issued and will entitle the holders of such Depositary Shares to the rights specified in the applicable Depositary Agreement and the applicable depositary receipts. 5. With respect to the Units, when (i) specifically authorized for issuance by the Authorizing Resolutions, (ii) the applicable Unit Agreement has been duly authorized, executed and delivered, (iii) the terms of the Units and of their issuance and sale have been duly established in conformity with the applicable Unit Agreement and the Authorizing Resolutions, (iv) the Units have been duly executed and delivered in accordance with the applicable Unit Agreement and issued and delivered as contemplated by the Registration Statement, the Prospectus and any applicable prospectus supplement in accordance with the applicable underwriting or other purchase agreement against payment therefor, and (v) the Company has received the consideration provided for in the Authorizing Resolutions and the applicable underwriting agreement or other purchase agreement, such Units will constitute valid and binding obligations of the Company enforceable against the Company in accordance with their terms. 6. With respect to the Warrants, when (i) specifically authorized for issuance by the Authorizing Resolutions, (ii) the applicable Warrant Agreement relating to the Warrants has been duly authorized, executed and delivered by the Company, (iii) the terms of the Warrants and of their issuance and sale have been duly established in conformity with the applicable Warrant Agreement and the Authorizing Resolutions, (iv) the Warrants have been duly executed by the Company and countersigned in accordance with the applicable Warrant Agreement and Authorizing Resolutions and issued and delivered as contemplated by the Registration Statement, the Prospectus and any applicable prospectus supplement in accordance with the applicable underwriting or other purchase agreement against payment therefor, and (v) the Company has received the consideration provided for in the Authorizing Resolutions
6 and the applicable underwriting agreement or other purchase agreement, such Warrants will constitute valid and binding obligations of the Company enforceable against the Company in accordance with their terms. I hereby consent to the filing of this opinion with the Commission as an exhibit to the Registration Statement and to the reference to me under the caption “Legal Matters” in the Registration Statement. By giving this consent, I do not admit that I am an expert with respect to any part of the Registration Statement, including this exhibit, within the meaning of the term “expert” as used in the Securities Act or the rules and regulations of the Commission issued thereunder. Sincerely, /s/ Daniel Woubishet Daniel Woubishet Associate General Counsel and Assistant Corporate Secretary
