X0303 4 2011-04-20 0 0001367644 Emergent BioSolutions Inc. EBS 0001380185 El-Hibri Fuad 2273 RESEARCH BOULEVARD, SUITE 400 ROCKVILLE MD 20850 1 1 1 0 CEO & Chairman Common Stock 2011-04-20 4 S 0 16438 24.0985 D 1128109 D Common Stock 1524155 I By Biovac, L.L.C Common Stock 6136794 I By Intervac, L.L.C Common Stock 10428 I By Karim El-Hibri Trust Common Stock 10428 I By Yusra El-Hibri Trust Common Stock 10428 I By Faiza El-Hibri Trust Common Stock 2265043 I By BioPharm,L.L.C. This price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $24.00 to $24.24. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by Mr. El-Hibri on March 14, 2011. Mr. El-Hibri's direct holdings include restricted stock units granted under the Amended and Restated Emergent BioSolutions Inc. 2006 Stock Incentive Plan. Mr. El-Hibri holds individually and with his wife, as tenants by the entirety, an aggregate 89.2% equity interest in Biovac, L.L.C. Biovac, L.L.C. is the direct owner of 1,524,155 shares of Common Stock. Mr. El-Hibri disclaims beneficial ownership of the shares of Common Stock directly owned by Biovac, L.L.C. for purposes of Section 16, except to the extent of his pecuniary interest in 1,359,546 shares. Mr. El-Hibri holds with his wife, as tenants by the entirety, an aggregate 41.1072% equity interest in Intervac, L.L.C. Mr. El-Hibri disclaims beneficial ownership of the shares of Common Stock directly owned by Intervac, L.L.C. for purposes of Section 16, except to the extent of his pecuniary interest in 2,522,665 shares. These shares are held in a trust for the benefit of a child of the reporting person. The reporting person is trustee of this trust. The reporting person disclaims beneficial ownership of these securities, and the filing of this report is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose. Mr. El-Hibri is the holder of a 40.17% (567,582.3 units) equity interest in BioPharm, L.L.C. BioPharm, L.L.C. is the direct owner of 2,265,043 shares of Common Stock. Mr. El-Hibri disclaims beneficial ownership of these shares for purposes of Section 16, except to the extent of his pecuniary interest in 909,868 shares. /s/ Carl A. Valenstein, attorney-in-fact 2011-04-22