United States securities and exchange commission logo

                           December 6, 2021

       Robert Hershberg, M.D., Ph.D.
       Chief Executive Officer
       HilleVax, Inc.
       75 State Street
       Suite 100 - #9995
       Boston, MA 02109

                                                        Re: HilleVax, Inc.
                                                            Amendment No. 1 to
                                                            Draft Registration
Statement on Form S-1
                                                            Submitted November
23, 2021
                                                            CIK No. 0001888012

       Dear Dr. Hershberg:

             We have reviewed your amended draft registration statement and
have the following
       comments. In some of our comments, we may ask you to provide us with
information so we
       may better understand your disclosure.

              Please respond to this letter by providing the requested
information and either submitting
       an amended draft registration statement or publicly filing your
registration statement on
       EDGAR. If you do not believe our comments apply to your facts and
circumstances or do not
       believe an amendment is appropriate, please tell us why in your

             After reviewing the information you provide in response to these
comments and your
       amended draft registration statement or filed registration statement, we
may have additional

       Draft Registration Statement on Form S-1 submitted November 23, 2021

       HIL-214 clinical data and development plan, page 4

   1.                                                   We note your response
to prior comment 4. Please also revise to specify the number of
                                                        adverse events observed
in your clinical trials for infant and adult subjects.
 Robert Hershberg, M.D., Ph.D.
FirstName  LastNameRobert Hershberg, M.D., Ph.D.
HilleVax, Inc.
December   NameHilleVax,
              2021        Inc.
Page 2     6, 2021 Page 2
FirstName LastName
Risk Factors, page 14

2.       We note your response to our prior comment 8. While it may not be
anticipated for the
         administrator of the 2022 Plan to exercise its discretion to amend any
outstanding stock
         option or SAR to reduce its price per share, we believe that it would
be appropriate to
         include risk factor disclosure to inform investors of the potential
impact and risks from the
         provision referred to in our prior comment. Please revise accordingly.
Dose finding and formulation trials in adults, page 118

3.       We note your response to our prior comment 15. Please revise to
clarify the type of
         placebo used, whether the trials were powered for statistical
significance, as applicable,
         and the number of participants who experienced the adverse effects
Intellectual Property, page 127

4.       We note your response to our prior comment 18. Please revise to
disclose the number of
         foreign granted patents and patent applications across the various
patent families, as
         applicable. We also note your disclosure on page 128 of six
in-licensed patent families
         covering VLP compositions and methods of use. To the extent known,
please expand
         your disclosure to provide a more detailed description of the products
or technologies to
         which each patent family relates.
Principal stockholders, page 176

5.       We note your response to prior comment 20. Please revise your disclose
to clarify who
         exercises voting or investment control over the shares held by Takeda
Vaccines, Inc. If
         the board of directors of Takeda Pharmaceutical Company Limited
exercises such control,
         please make that clear.
       You may contact Julie Sherman at 202-551-3640 or Terence O'Brien at
202-551-3355 if
you have questions regarding comments on the financial statements and related
matters. Please
contact Jane Park at 202-551-7439 or Tim Buchmiller at 202-551-3635 with any
other questions.


                                                               Division of
Corporation Finance
                                                               Office of Life
cc:      Cheston J. Larson, Esq.