X0306 4 2018-02-15 0 0000353569 QUIDEL CORP /DE/ QDEL 0001655234 Russell Edward Keith 12544 HIGH BLUFF DRIVE SUITE 200 SAN DIEGO CA 92130 0 1 0 0 S.V.P., N.A. Commercial Ops Common Stock 2018-02-15 4 A 0 7171 0.00 A 8648 D Common Stock 2018-02-15 4 F 0 2471 45.10 D 6177 D Common Stock 2018-02-17 4 A 0 3646 0.00 A 9823 D Common Stock 2018-02-17 4 F 0 1175 45.87 D 8648 D Common Stock 2018-02-17 4 A 0 364 0.00 A 9012 D Common Stock 2018-02-17 4 F 0 125 45.87 D 8887 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. 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. Reflects vesting of restricted stock units, which were previously reported on a Form 4. 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 restricted stock units. Robert J. Bujarski, attorney-in-fact for Edward K. Russell 2018-02-20