Vertex Pharmaceuticals (VRTX) 10-Q 2004 Q2 Quarterly report

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Exhibit 32.1

Certification
Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
(Subsections (a) and (b) of Section 1350,
Chapter 63 of Title 18, United States Code)

        Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of Section 1350, Chapter 63 of Title 18, United States Code), each of the undersigned officers of Vertex Pharmaceuticals Incorporated, a Massachusetts corporation (the "Company"), does hereby certify, to such officer's knowledge, that the Quarterly Report on Form 10-Q for the quarter ended June 30, 2004 (the "Form 10-Q") of the Company fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and the information contained in the Form 10-Q fairly presents, in all material respects, the financial condition and results of operation of the Company.

Dated: August 9, 2004	/s/  JOSHUA S. BOGERJoshua S. Boger Chairman and Chief Executive Officer (principal executive officer)
Dated: August 9, 2004	/s/  IAN F. SMITH      Ian F. Smith Senior Vice President and Chief Financial Officer (principal financial officer)

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Exhibit 32.1