X0306 4 2018-02-15 0 0000353569 QUIDEL CORP /DE/ QDEL 0001609320 Kroll Werner 12544 HIGH BLUFF DRIVE, SUITE 200 SAN DIEGO CA 92130 0 1 0 0 SVP, R&D Common Stock 2018-02-15 4 A 0 7171 0.00 A 13827 D Common Stock 2018-02-15 4 F 0 2479 45.10 D 11348 D Reporting Person acquired these shares in connection with full achievement of performance metrics associated with performance-based restricted stock units awarded on 2/15/2017. The amount of securities beneficially owned prior to this transaction included an additional 664 shares due to the Reporting Person's purchase of shares pursuant to the Issuer's Employee Stock Purchase Plan. 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 release of performance-based restricted stock units. Robert J. Bujarski, attorney-in-fact for Werner Kroll 2018-02-20