Sec Form 4 Filing - WIDDER KENNETH J @ QUIDEL CORP /DE/ - 2022-05-27

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 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

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1. Name and Address of Reporting Person WIDDER KENNETH J 2. Issuer Name and Ticker or Trading Symbol QUIDEL CORP /DE/ [ QDEL] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 9975 SUMMERS RIDGE ROAD 3. Date of Earliest Transaction (MM/DD/YY) 05/27/2022 (Street) SAN DIEGO, CA92121 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 Common Stock 05/27/2022 D( 1 ) 18,684 D 0 D

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 Non-Qualified Stock Options $ 27.91 05/27/2022 D( 2 ) 3,333 ( 3 ) 11/17/2024 Common Stock 3,333 $ 0 0 D Non-Qualified Stock Options $ 22.86 05/27/2022 D( 2 ) 7,021 ( 3 ) 05/05/2025 Common Stock 7,021 $ 0 0 D Non-Qualified Stock Options $ 15.74 05/27/2022 D( 2 ) 7,021 ( 3 ) 05/17/2026 Common Stock 7,021 $ 0 0 D Non-Qualified Stock Options $ 24.8 05/27/2022 D( 2 ) 5,065 ( 3 ) 05/16/2027 Common Stock 5,065 $ 0 0 D Restricted Stock Units ( 4 ) 05/27/2022 D( 5 ) 1,050 ( 6 ) ( 6 ) Common Stock 1,050 $ 0 0 D Restricted Stock Units ( 4 ) 05/27/2022 D( 5 ) 315 ( 6 ) ( 6 ) Common Stock 315 $ 0 0 D Restricted Stock Units ( 4 ) 05/27/2022 D( 5 ) 328 ( 6 ) ( 6 ) Common Stock 328 $ 0 0 D Restricted Stock Units ( 4 ) 05/27/2022 D( 5 ) 98 ( 6 ) ( 6 ) Common Stock 98 $ 0 0 D Restricted Stock Units ( 4 ) 05/27/2022 D( 5 ) 512 ( 6 ) ( 6 ) Common Stock 512 $ 0 0 D Restricted Stock Units ( 4 ) 05/27/2022 D( 5 ) 153 ( 6 ) ( 6 ) Common Stock 153 $ 0 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other WIDDER KENNETH J 9975 SUMMERS RIDGE ROAD SAN DIEGO, CA92121 X Signatures /s/ Phillip S. Askim, attorney-in-fact for Kenneth J. Widder 06/01/2022 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Pursuant to the Business Combination Agreement, dated as of December 22, 2021 (the "Business Combination Agreement") by and among Quidel Corporation ("Quidel"), Ortho Clinical Diagnostics Holdings plc, QuidelOrtho Corporation ("QuidelOrtho"), Orca Holdco, Inc., Laguna Merger Sub, Inc. and Orca Holdco 2, Inc., each share of common stock of Quidel beneficially owned by the Reporting Person at the effective time of the transaction contemplated by the Business Combination Agreement will be exchanged for one share of common stock of QuidelOrtho. ( 2 )Pursuant to the Business Combination Agreement, the Quidel Non-Qualified Stock Options will be converted into an equal number of Non-Qualified Stock Options to purchase shares of common stock of QuidelOrtho on the same terms and conditions (including applicable vesting conditions). ( 3 )Vested in full. ( 4 )Each restricted stock unit represents the right to receive one share of Quidel common stock. ( 5 )Pursuant to the Business Combination Agreement, the Quidel restricted stock units will be converted into an equal number of restricted stock units representing the right to receive shares of common stock of QuidelOrtho on the same terms and conditions (including applicable vesting conditions). ( 6 )Release of restricted stock units was deferred pursuant to Quidel's deferred compensation program applicable to participating non-employee directors and will occur according to the elected deferral schedule.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* 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).

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