SecProbe.io

Mail Stop 6010

        October 11, 2006

Fuad El-Hibri
Chief Executive Officer
Emergent BioSolutions Inc.
300 Professional Drive, Suite 250
Gaithersburg, Maryland  20879

 Re: Emergent BioSolutions Inc.
  Amendment No. 1 to the Registration Statement on Form S-1
  Filed September 25, 2006
  File No. 333-136622

Dear Mr. El-Hibri:

 We have reviewed your filing and have th e following comments.  Where indicated, we
think you should revise your document in response to these comments.  If you disagree, we will
consider your explanation as to why our commen t is inapplicable or a revision is unnecessary.
Please be as detailed as necessa ry in your explanation.  In some  of our comments, we may ask
you to provide us with information so we may better understand your disclosure.  After
reviewing this information, we may raise additional comments.

 Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure requir ements and to enhance the overall disclosure in
your filing.  We look forward to working with you in these respects.  We welcome any questions
you may have about our comments or any other aspect of our review.  Feel fr ee to call us at the
telephone numbers listed at the end of th is letter.

Form S-1/#1

Our Business, page 1

1. We note your response to comment 10. Please te ll us if the IND filed by Microscience
and that which is currently held by Emergent Product Development UK is for an IND
filed with the FDA in the United States or wi th a similar agency in a foreign country.

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Our Strategy, page 3

2. We note your response to comment 12 and reis sue the comment. The discussion of the
risks and obstacles you will face in implementing your strategy should be as prominent as
the discussion of your strategy.  Please revi se the discussion of the risks you face to
include a similar level of detail fo r each of the risks you identify.

We will not be able to commercialize our pr oduct candidates if our preclinical development
efforts are not successful, …, page 20
3. We note your statement in your response to comment 27 that you have had discussions
with the FDA relating to the design of your Ph ase I clinical trial.  Did the FDA indicate
that it would not require a Phase II clinical trial?

Use of Proceeds, page 45

4. We note your response to comment 50 and your revised disclosure. However, our
comment sought for you to provide disclosure  on how much you anticipate spending for
each product candidate and where in the develo pment process you expect to be after the
expenditure of these proceeds. Therefore, our comment is reissued in part. Please revise
this section accordingly. Please also provide the approximate timing of these expenditures.

License Agreements, page 111

5. We note your response to comment 63. We not e your revised disclo sure that you have
paid $1.0 million minimum contractual commitments for each of the two developmental
agreements you entered with HPA. Please di sclose any amounts you have paid HPA to
date with respect to the license agreements you have with them. You also indicate that
with respect to the license ag reement with HPA that if you fa il to file an IND within a
certain time period under either of your license agreement with HPA that you are
obligated to pay HPA an annual fee until an  IND has been filed. Please disclose the
annual fee amount, if such amount is material.

Typhoid Vaccine, page 96
Hepatitis B therapeutic vaccine, page 98
Group B streptococcus, page 100
Chlamydia vaccine, page 102
Meningitis B vaccine, page 94
6. We note your response to comment 69.  To the ex tent that the data from your clinical
trials was analyzed for immunogenicity, the resu lts of these analyses should be disclosed
with the related p values and statements that  they are merely indications of efficacy and
not sufficient to enable a product to proceed  to Phase II clinical development.

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Management’s discussion and analysis of financial condition
Critical accounting policies and estimates
Revenue recognition, page 56

7. We have reviewed your response to commen t number 54.  Please disclose within your
document similar information regarding the FDA review process as you have presented
within your response.  In a ddition, please disclose the number of instances, if any, that
the FDA has denied sale of BioThrax and the effect on the financial statements of such
denial.  Lastly, please descri be to us, and disclose, the poi nt at which you capitalize cost
as inventory.  Given that you are unable to sell BioThrax until you have received FDA
approval, please tell us how these costs meet the definition of an asset as described in
paragraph 26 of CON 6.  Specifically, addre ss your ability to es timate the likelihood of
obtaining FDA approval in determining whether there is a future economic benefit.

Stock-based compensation, page 58

8. Refer to your response to previous comment 54.  We continue to believe that you have
used an “independent valuation specialist” as an expert to help determine the fair value of
your equity securities.  Please name the independent valuation sp ecialists and provide
written consents, as appropriate, or provide to us a more robust and detailed analysis of Rule 436, including considera tion of footnote 60 of the AICPA Practice Aid, which
supports management’s current determination th at the independent valu ation specialist is
not an expert.

Financial operations overview
Revenues, page 60
9. We note your added disclosures regarding your expectation of successful delivery of the
required 1 million doses of BioThrax to the DoD during the three month period ended
September 30, 2006.  Please update your disc losures to indicate whether you were
successful in delivering these doses.  If you were unable to deliver th e doses as required,
please disclose the implications of non-perfor mance, including any effect on the financial
statements that will be reflected in the September 30, 2006 financial statements.
10. Given the wide disparity in the price per dose charge under the HHS and DoD contracts,
please revise your disclosure to discuss significant changes in pri ce separate from your
current discussion of volume.

Contractual Obligations, page 73
11. We have reviewed your response to commen t number 58.  Please disclose within the
footnote to the table, the material royalties and milestones related to current development
programs that the Company estimated are not probable to occur and the basis for management’s decision.

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Selling Shareholders, page 157
12. We note your response to comment 74 and your  response that Microscience Investment
“may” be an affiliate of a broker-dealer.  Please determine if Microscience Investment is
an affiliate of a broker-dealer and if they are considered an affiliate of a broker-dealer, please revise your disclosure to include the following representations:

• The selling security holder purchased in the ordinary course of business; and
• At the time of the purchase, the selli ng security holder had no agreements or
understanding to distri bute the securities.

If you are unable to make these statements in  the prospectus, please revise the prospectus
to state the seller sharehol der is an underwriter.

Nature of the business and organization, page F-7
13. We have reviewed your response to commen t number 78.  Please note that Article 11-
01(d) of Regulation S-X states that a “pre sumption exists that a separate entity, a
subsidiary, or a division is a business.”  Additionally, in appears based upon your response that Microscience possessed physical facilities, employee base, operating rights,
and production techniques. Accordingly, please provide additional information as to why financial statements for Microscience have not been provided in accordance with Rule 3-
05 of Regulation S-X.  Please note that the determination of a business under EITF 98-3
and SFAS 141 is irrelevant to this analysis.

Exhibits

14. We note that a number of your agreements will be filed by amendment, including the form of underwriting agreement. Please file as  promptly as possible all exhibits as we
will need to review them prio r to granting effectiveness of the registration statement. In
that regard, to the extent you are able to provide us with a supplemental copy of the
underwriting agreement, this may expedite our review of your filing.

* * *

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As appropriate, please amend your registration statement in response to these comments.
You may wish to provide us with marked copies  of the amendment to expedite our review.
Please furnish a cover letter with  your amendment that keys your responses to our comments and
provides any requested supplemental information.  Detailed cover letters greatly facilitate our
review.  Please furnish your letter to us vi a EDGAR under the form type label CORRESP. Please
understand that we may have additional comm ents after reviewing your amendment and
responses to our comments.

You may contact Todd Sherman at (202) 551-3665 or Kevin Woody, Accounting Branch
Chief at (202) 551-3629 if you have questions re garding comments on the financial statements
and related matters.  Please contact Song Brandon at (202) 551-3621, Suzanne Hayes, Legal
Branch Chief at (202) 551-3675, or me at  (202) 551-3715 with any other questions.

        S i n c e r e l y ,

        J e f f r e y  R i e d l e r
        A s s i s t a n t  D i r e c t o r

cc: David Redlick
 Brian A. Johnson
 Wilmer Cutler Hale and Dorr LLP
 1875 Pennsylvania Ave., NW
 Washington, DC 20006

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