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.

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                                   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