UNITED STATES
                          SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON, D.C.  20549

                                     FORM 10-Q/A


[X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     EXCHANGE ACT OF 1934

For the quarterly period ended September 30, 1997

                                          or

[ ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     EXCHANGE ACT OF 1934

                           Commission File Number:  0-21088

                                  VICAL INCORPORATED
      -------------------------------------------------------------------------
                (Exact name of registrant as specified in its charter)

               Delaware                              93-0948554
- --------------------------------------------------------------------------------
(State or other  jurisdiction of        (I.R.S. Employer Identification No.)
incorporation or organization)

9373 Towne Centre Dr., Suite 100, San Diego, California          92121
- --------------------------------------------------------------------------------
(Address of principal executive offices)                       (Zip code)

                                    (619) 453-9900
- --------------------------------------------------------------------------------
                 (Registrant's telephone number, including area code)

                                    Not Applicable
- --------------------------------------------------------------------------------
(Former name, former address and former fiscal year, if changed since last
report)

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or such shorter period that the registrant was required
to file such reports), and (2) has been subject to such filing requirements for
the past 90 days  --  Yes X    No   .
                         ---     ---

Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the latest practicable date.

          Class                            Outstanding at September 30, 1997
          -----                            ---------------------------------
Common Stock, $.01 par value                           15,460,802


                                  VICAL INCORPORATED

                                     FORM 10-Q/A

                                  TABLE OF CONTENTS


                                                                      PAGE NO.
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COVER PAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

TABLE OF CONTENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . .2


PART II.  OTHER INFORMATION

     ITEM 6.  Exhibits and Reports on Form 8-K . . . . . . . . . . . . . .3

SIGNATURE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

EXHIBIT LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5


                                          2


PART II.  OTHER INFORMATION
ITEM 6.   EXHIBITS AND REPORTS ON FORM 8-K


1.   Exhibits

     EXHIBIT 10.18  #  Agreement between Merck & Co. Inc. and the Company dated
     September 12, 1997.

     #  Confidential treatment has been requested with respect to certain
     portions of this agreement.

     EXHIBIT 27     Financial Data Schedule

2.   Reports on Form 8-K

        None


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                                  VICAL INCORPORATED



                                      SIGNATURES



Pursuant to the requirements of the Securities and Exchange Act of 1934, the
registrant has duly caused this report to be signed in its behalf by the
undersigned thereunto duly authorized.


                                             Vical Incorporated


Date:  January 30, 1998                      By: s/Martha J. Demski
                                                -------------------
                                                Martha J. Demski
                                                Vice President and
                                                Chief Financial Officer
                                                (on behalf of the registrant and
                                                as the registrant's Principal
                                                Financial and Accounting
                                                Officer)


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          EXHIBIT
          NUMBER                             DESCRIPTION OF DOCUMENT
          -------                            -----------------------

1.   EXHIBIT 10.18  #              Agreement between Merck & Co. Inc. and the
                                   Company dated September 12, 1997

     EXHIBIT 27
                                   Financial Data Schedule

#  Confidential treatment has been requested with respect to certain portions of
   this agreement.


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