Exhibit 16.1
November 4, 2009
Securities and Exchange Commission
100 F Street, N.E.
Washington, DC 20549
Dear Sirs/Madams:
We have read Item 4 of the Merck & Co., Inc. (formerly known as Schering-Plough Corporation) Form 8-K dated November 4, 2009 and agree with the statements made therein.
Yours truly,
/s/ Deloitte & Touche LLP
Parsippany, New Jersey