United States securities and exchange commission logo

                           March 15, 2022

       Andrew Allen
       President and Chief Executive Officer
       Gritstone bio, Inc.
       5959 Horton Street, Suite 300
       Emeryville, California 94608

                                                        Re: Gritstone bio, Inc.
Statement on Form S-3
                                                            Filed March 10,
                                                            File No. 333-263455

       Dear Dr. Allen:

              This is to advise you that we have not reviewed and will not
review your registration

               Please refer to Rules 460 and 461 regarding requests for
acceleration. We remind you
       that the company and its management are responsible for the accuracy and
adequacy of their
       disclosures, notwithstanding any review, comments, action or absence of
action by the staff.

                                                        Please contact Gary
Guttenberg at (202) 551-6477 with any questions.


                           Division of Corporation Finance

                           Office of Life Sciences
       cc:                                              Brian Cuneo