X0306 4 2021-09-09 0 0001532346 Atreca, Inc. BCEL 0001477384 Orwin John A C/O ATRECA, INC., 835 INDUSTRIAL RD. SUITE 400 SAN CARLOS CA 94070 1 1 0 0 President & CEO Class A Common Stock 2021-09-09 4 A 0 115400 0.00 A 121400 D The shares of common stock are to be acquired upon the vesting of a restricted stock unit award granted to the Reporting Person. The restricted stock unit award shall vest as follows: vest over two years (vesting commencement date = September 1, 2021), with a one-year cliff as follows: on the first anniversary of the vesting commencement date, 50% of the restricted stock unit award shall vest, and on the second anniversary of the vesting commencement date, 50% of the restricted stock unit award shall vest. In total, 100% of the restricted stock unit award shall be vested on the second anniversary of the vesting commencement date. /s/ Courtney Phillips, Attorney-In-Fact 2021-09-13