Exhibit 99.(a)(17)
CHIRON CORPORATION
4560 Horton Street
Emeryville, California 94608
March 17, 2006
Dear Fellow Stockholder:
We have previously sent to you proxy material for the Special Meeting of Chiron Corporation, scheduled to be held on April 12, 2006. Your Board of Directors has unanimously recommended that shareholders vote FOR the merger with Novartis Corporation.
Since approval of the merger requires the affirmative vote of at least a majority of outstanding shares, your vote is important, no matter how many or how few shares you may own. Whether or not you have already done so, please vote TODAY by telephone, via the Internet, or by signing, dating and returning the enclosed proxy card in the envelope provided.
Very truly yours,
Howard H. Pien
Chairman of the Board and
Chief Executive Officer
REMEMBER:
You can vote your shares by telephone, or via the Internet.
Please follow the easy instructions on the enclosed card.
If you have any questions, or need assistance in voting
your shares, please call our proxy solicitor,
INNISFREE M&A INCORPORATED
TOLL-FREE, at 1-888-750-5835.