POWER OF ATTORNEY



Know all by these presents, that the undersigned hereby constitutes and appoints each of Stefan Ryser

and Dorigen Horlivy, singing singly, his/her true and lawful attorney-in-fact to:



(1) execute for and on behalf of the undersigned Forms 3, 4, and 5 with respect to the securities of

PharmAthene, Inc. (formerly Healthcare Acquisition Corp.) in accordance with Section 16(a) of the

Securities Exchange Act of 1934 and the rules thereunder;



(2) do and perform any and all acts for and on behalf of the undersigned which may be necessary or

desirable to complete and execute any such Form 3, 4, or 5, the timely filing of such form with the

United States Securities and Exchange Commission and any other authority; and



(3) take any other action of any type whatsoever in connection with the foregoing which, in the opinion

of such attorney-in-fact, may be of benefit to, in the best interest of, or legally required by, the

undersigned, it being understood that the documents executed by such attorney-in-fact on behalf of the

undersigned pursuant to this Power of Attorney shall be in such form and shall contain such terms and

conditions as such attorney-in-fact may approve in his or her discretion.



 The undersigned hereby grants to each such attorney-in-fact full power and authority to do and

perform any and every act and thing whatsoever requisite, necessary, or proper to be done in the exercise

of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned

might or could do if personally present, with full power of substitution or revocation, hereby ratifying

and confirming all that such attorney-in-fact, or such attorney-in-fact's substitute or substitutes, shall

lawfully do or cause to be done by virtue of this power of attorney and the rights and powers herein granted.

The undersigned acknowledges that the foregoing attorneys-in-fact, in serving in such capacity at the request

of the undersigned, are not assuming, nor is the Company assuming, any of the undersigned's responsibilities

to comply with Section 16 of the Securities Exchange Act of 1934.



This Power of Attorney shall remain in full force and effect until the undersigned is no longer required to

file Forms 3, 4, and 5 with respect to the undersigned's holdings of and transactions in securities issued

by the Company, unless earlier revoked by the undersigned in a signed writing delivered to the foregoing

attorneys-in-fact.



IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of this 26th day

of July, 2007.



 Elizabeth Czerepak