November 7, 2019

Grant E. Pickering
President and Chief Executive Officer
SutroVax, Inc.
353 Hatch Drive
Foster City, California 94404

       Re: SutroVax, Inc.
           Draft Registration Statement on Form S-1
           Submitted October 11, 2019
           CIK No. 0001649094

Dear Mr. Pickering:

       We have reviewed your 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
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 response.

      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

Prospectus Summary, page 1

1.     Please revise your statement here and elsewhere in the prospectus that
SVX-24 has the
       potential to become the "standard of care." This statement implies an
expectation of
       regulatory approval and is inappropriate given the length of time and
uncertainty with
       respect to securing marketing approval.
Our Pipeline, page 3

2.     Please remove your statement that you believe that your preclinical
study results may be
       predictive of clinical trial results based on your use of the same
rabbit model used to
       develop each of the PCVs approved to date. It is not appropriate to
imply that success in
 Grant E. Pickering
SutroVax, Inc.
November 7, 2019
Page 2
         animal models may result in success in humans.
3.       Please expand to state whether you have received any feedback from the
FDA as to
         whether they would accept your intended approach of seeking regulatory
approval based
         on a demonstration of non-inferiority to the standard of care rather
than on clinical field
         efficacy studies.
Our Strategy, page 4

4.       We note your disclosure that your strategy is to "rapidly advance"
SVX-24 through IND-
         enabling activities, clinical development and regulatory approval.
Please revise this
         statement and any similar disclosure to remove any implication that
you will be successful
         in commercializing your product candidates in a rapid or accelerated
manner as such
         statements are speculative.
Risk Factors Summary, page 5

5.       We note several statements in the prospectus, including in a risk
factor, regarding
         pursuing a streamlined approach to regulatory approval of your
vaccines based on how
         other vaccines have obtained regulatory approval. Please add a risk
factor to this section
         to make it clear that there can be no assurance that your intended
approach will be
         sufficient for regulatory approval or that regulators will not require
field efficacy trials
         or longer trials with more participants than you currently anticipate.
Implications of Being an Emerging Growth Company, page 7

6.       Please supplementally provide us with copies of all written
communications, as defined in
         Rule 405 under the Securities Act, that you, or anyone authorized to
do so on your behalf,
         present to potential investors in reliance on Section 5(d) of the
Securities Act, whether or
         not they retain copies of the communications.
Use of Proceeds, page 66

7.       We note your disclosure that you intend to use a portion of the
proceeds to fund the
         clinical and ongoing development of your vaccine candidates. Please
specifically disclose
         how far you expect the proceeds from the offering to allow you to
proceed in the
         development of each of these candidates.
FirstName for Current PCVs, page 102
DrawbacksLastNameGrant E. Pickering
Comapany NameSutroVax, Inc. under the charts in Figure 4 and Figure 5 on page
103 more
8.   Please make the disclosure
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FirstName LastName
 Grant E. Pickering
FirstName Inc.
SutroVax, LastNameGrant E. Pickering
Comapany 7, 2019
November NameSutroVax, Inc.
Page 3
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FirstName LastName
Intellectual Property, page 118

9.       Please specify to which of your product candidates your pending and
current patents
Amended and Restated Agreement with Sutro Biopharma, page 119

10.      We note your disclosure that royalties are payable until the later of
the expiration of the
         last valid claim in the licensed patents or 10 years after the first
commercial sale. Please
         specify when the licensed patents are expected to expire.
University of California, San Diego License Agreement, page 120

11.      We note your disclosure that royalties are payable until expiration of
the last licensed
         patent. Please specify when the current last licensed patent is
expected to expire.
Principal Stockholders, page 156

12.      We note your disclosure regarding certain individuals who share or may
be deemed to
         share investment and dispositive power over the shares held by certain
entities. It is not
         clear whether those are the sole individuals who have voting and
investment control. In
         that regard, please revise your disclosure to identify all of the
natural person or
         persons who have voting and investment control of the shares held by
         Bioventures VI, LP, Longitude Venture Partners II, L.P., and TPG
Growth IV Switcheroo,
Description of Capital Stock, page 158

13.      We note that you refer shareholders to, in part, the relevant
provisions of the Delaware
         General Corporation Law. It is not appropriate to qualify your
disclosure by reference to
         information that is not included in the filing or filed as an exhibit.
Please revise

14.      Please provide us proofs of all graphics, visual, or photographic
information you will
         provide in the printed prospectus prior to its use, for example in a
preliminary prospectus.
         Please note that we may have comments regarding this material.
 Grant E. Pickering
FirstName Inc.
SutroVax, LastNameGrant E. Pickering
Comapany 7, 2019
November NameSutroVax, Inc.
Page 4
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FirstName LastName
       You may contact Michael Fay at 202-551-3812 or Al Pavot at 202-551-3738
if you have
questions regarding comments on the financial statements and related matters.
Please contact
Ada D. Sarmento at 202-551-3798 or Mary Beth Breslin at 202-551-3625 with any


                                                         Division of
Corporation Finance
                                                         Office of Life
cc:      Robert W. Phillips, Esq.