Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0287
Expires: January 31, 2005
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
SOLAND DANIEL B
   2. Issuer Name and Ticker or Trading Symbol
CHIRON CORP [CHIR] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
VP; President, Chiron Vaccines
(Last)
(First)
(Middle)
4560 HORTON STREET		 3. Date of Earliest Transaction (Month/Day/Year)
04/19/2006
(Street)

EMERYVILLE, CA 94608		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Employee Stock Option (Right to Buy) $ 35.74 04/19/2006   D(1)     200,000   (2) 04/19/2006 Common Stock 200,000 $ 12.26 (1) 0 D  
Performance Share Rights Award (3) 04/19/2006   A(4)   14,000     (5) 04/19/2006 Common Stock 14,000 $ 0 14,000 D  
Performance Share Rights Award (3) 04/19/2006   D(6)     14,000   (5) 04/19/2006 Common Stock 14,000 $ 48 (6) 0 D  
Restricted Stock Units (3) 04/19/2006   D(7)     2,200   (8) 04/19/2006 Common Stock 2,200 $ 48 (7) 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
SOLAND DANIEL B
4560 HORTON STREET
EMERYVILLE, CA 94608		       VP; President, Chiron Vaccines  

Signatures

 Daniel B. Soland by Naima Robinson as Attorney-in-Fact   04/20/2006
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) The option was cancelled pursuant to the terms of the Merger Agreement in exchange for a cash payment per cancelled option share equal to $48 less the exercise price per share in effect for that option. Such disposition of the option was approved by the Compensation Committee of the Issuer's Board of Directors and is accordingly an exempt transaction pursuant to SEC Rule 16b-3(e).
(2) The option was vested and fully exercisable as to all the shares at the time of cancellation.
(3) One-for-One
(4) Represents a performance share award made on February 28, 2006 and structured to vest upon the Issuer's attainment of certain pre-established performance objectives over a designated period measured from February 28, 2005 to August 27, 2007. However, pursuant to the terms of such award, vesting occurred at target level on an accelerated basis immediately prior to the change in control transaction effected on April 19, 2006 pursuant to the Merger Agreement. The award was made to the Reporting Person in a transaction exempt under SEC Rule 16b-3(d).
(5) The share rights award vested in full on an accelerated basis immediately prior to the closing of the change in control transaction effected on April 19, 2006 pursuant to the Merger Agreement.
(6) The share rights were cancelled pursuant to the terms of the Merger Agreement in exchange for a cash payment equal to $48 per share of the Issuer's common stock underlying the cancelled share rights. Such disposition of the share rights was approved by the Compensation Committee of the Issuer's Board of Directors and is accordingly an exempt transaction pursuant to SEC Rule 16b-3(e).
(7) The stock units were cancelled pursuant to the terms of the Merger Agreement in exchange for a cash payment equal to $48 per share of the Issuer's common stock underlying the cancelled share rights. Such disposition of the share rights was approved by the Compensation Committee of the Issuer's Board of Directors and is accordingly an exempt transaction pursuant to SEC Rule 16b-3(e).
(8) The stock units vested in full on an accelerated basis in connection with the closing of the change in control transaction effected on April 19, 2006 pursuant to the Merger Agreement.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.