As filed with the Securities and Exchange Commission on May 15, 2006. Registration No. 333-28257 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 POST-EFFECTIVE AMENDMENT TO FORM S-8 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 NOVARTIS VACCINES AND DIAGNOSTICS, INC. (Exact name of registrant as specified in its charter) Delaware (State or other jurisdiction of incorporation or organization) 94-2754624 (I.R.S. Employer Identification No.) 4560 Horton Street Emeryville, CA 94608 (510) 655-8730 (Address, including zip code, and telephone number, including area code, of registrant's principal executive offices) CHIRON 1991 STOCK OPTION PLAN (Full Title of Plan) Thomas Kendris, Esq. Vice President, General Counsel and Secretary Novartis Vaccines and Diagnostics, Inc. 4560 Horton Street Emeryville, CA 94608 (510) 655-8730 (Name, address, including zip code, and telephone number, including area code, of agent for service) TERMINATION OF REGISTRATION This Post-Effective Amendment No. 1 relates to the Registration Statement on Form S-8 (File No. 333-28257) filed on June 2, 1997, pertaining to the Common Stock of the Registrant, formerly known as Chiron Corporation, to be offered under the 1991 Stock Option Plan of Chiron Corporation. The undersigned Registrant hereby removes and withdraws from registration all securities registered pursuant to this Registration Statement that remain unissued. PAGE> SIGNATURES Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Post-Effective Amendment to the registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Emeryville, County of Alameda, State of California on May 15, 2006. NOVARTIS VACCINES AND DIAGNOSTICS, INC. By: /s/ Thomas Kendris ------------------------------------------------- Name: Thomas Kendris Title: Vice President and Secretary Pursuant to the requirements of the Securities Act of 1933, this Post-Effective Amendment to the registration statement has been signed by the following persons in the capacities and on the dates indicated: By: /s/ Joerg Reinhardt ------------------------------------------------- Name: Joerg Reinhardt Title: Director, President and Chief Executive Officer (Principal Executive Officer) Date: May 15, 2006 By: /s/ Reto Braendli ------------------------------------------------- Name: Reto Braendli Title: Vice President and Chief Financial Officer (Principal Financial and Accounting Officer) Date: May 15, 2006 By: /s/ Raymund Breu ------------------------------------------------- Name: Raymund Breu Title: Director Date: May 15, 2006 By: /s/ Paulo Costa ------------------------------------------------- Name: Paulo Costa Title: Director Date: May 15, 2006