Statement of Changes in Beneficial Ownership (4)

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
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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^* Kroll Werner	2. Issuer Name and Ticker or Trading Symbol QUIDEL CORP /DE/ [ QDEL ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) SVP, R&D
(Last) (First) (Middle) 9975 SUMMERS RIDGE ROAD	3. Date of Earliest Transaction (MM/DD/YYYY) 5/22/2020
(Street) SAN DIEGO, CA 92121 (City) (State) (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. 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)
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	5/22/2020		M		17596	A	$23.41	22195 ⁽¹⁾	D
Common Stock	5/22/2020		M		35192	A	$15.40	57387	D
Common Stock	5/22/2020		M		10758	A	$21.08	68145	D
Common Stock	5/22/2020		M		4606	A	$46.41	72751	D
Common Stock	5/22/2020		S		68152	D	$174.4358 ⁽²⁾	4599	D
Common Stock	5/27/2020		M		4376 ⁽³⁾	A	$0.00	8975	D
Common Stock	5/27/2020		F		2304 ⁽⁴⁾	D	$0.00	6671	D

*Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)*
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. 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		7. Title and Amount of Securities Underlying Derivative Security (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)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)			11. Nature of Indirect Beneficial Ownership (Instr. 4)
Non-Qualified Stock Options	$23.41	5/22/2020		M			17596	⁽⁵⁾	2/5/2025	Common Stock	17596	$0.00	0	D
Non-Qualified Stock Options	$15.40	5/22/2020		M			35192	⁽⁶⁾	2/10/2026	Common Stock	35192	$0.00	0	D
Non-Qualified Stock Options	$21.08	5/22/2020		M			10758	⁽⁷⁾	2/15/2027	Common Stock	10758	$0.00	3585	D
Non-Qualified Stock Options	$46.41	5/22/2020		M			4606	⁽⁸⁾	1/16/2028	Common Stock	4606	$0.00	4606	D
Restricted Stock Units	⁽⁹⁾	5/27/2020		M			4376	⁽¹⁰⁾	⁽¹⁰⁾	Common Stock	4376	$0.00	8752	D

Explanation of Responses:
(1)	The amount of securities beneficially owned following this transaction include an additional 272 shares due to the Reporting Person's purchase of shares pursuant to the Issuer's Employee Stock Purchase Plan.
(2)	The weighted average sale price for these transactions was $174.4358 per share, with a range of $171.69 to $180.50. Upon request, the Reporting Person hereby undertakes to provide to staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder, the full information regarding the number of shares sold at each separate price.
(3)	Reflects release of restricted stock units that were previously reported on Form 4.
(4)	The disposition of shares, as set forth above, was in connection with the Issuer's withholding of common shares to satisfy tax withholding obligations related to the issuance of common shares upon vesting of restricted stock units.
(5)	17,596 shares vested on 02/05/2017; 8,798 shares vested on 02/05/2018; and 8,798 shares vested on 02/05/2019.
(6)	17,596 shares vested on 02/10/2018; 8,798 shares vested on 02/10/2019; and 8,798 shares vested on 02/10/2020.
(7)	7,172 shares vested on 02/15/2019; 3,586 shares vested on 02/15/2020; and 3,585 shares will vest on 02/15/2021.
(8)	4,606 shares vested on 01/16/2020; 2,303 shares will vest on 01/16/2021; and 2,303 shares will vest on 01/16/2022.
(9)	Restricted stock units convert into common stock on a one-for-one basis.
(10)	On 05/27/2014, the Reporting Person was granted 17,505 restricted stock units vesting as follows: 4,377 shares vested on 05/27/2019; 4,376 shares vested on 05/27/2020; 4,376 shares will vest on 05/27/2021; and 4,376 shares will vest on 05/27/2022.

Remarks:
All transactions occurring on May 22, 2020 were effected pursuant to a pre-established 10b5-1 trading plan

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
Kroll Werner 9975 SUMMERS RIDGE ROAD SAN DIEGO, CA 92121			SVP, R&D