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                           August 10, 2020

       Carsten Brunn, Ph.D.
       President and Chief Executive Officer
       Selecta Biosciences, Inc.
       65 Grove Street
       Watertown, MA 02472

                                                        Re: Selecta
Biosciences, Inc.
                                                            Registration
Statement on Form S-3
                                                            Filed August 6,
2020
                                                            File No. 333-241692

       Dear Dr. Brunn:

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

               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 Jeffrey
Gabor at 202-551-2544 with any questions.




                           Sincerely,


                           Division of Corporation Finance

                           Office of Life Sciences
       cc:                                              Wesley C. Holmes, Esq.