<PAGE>
 
                                  EXHIBIT 4.6

                             EXHIBIT B (WARRANT #4)

     THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED (THE "ACT"), OR APPLICABLE STATE SECURITIES
LAWS (COLLECTIVELY, THE "LAWS"). THE SECURITIES HAVE BEEN ACQUIRED FOR
INVESTMENT AND MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED IN THE
ABSENCE OF EITHER (I) AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES
UNDER THE LAWS, OR (II) AN OPINION OF COUNSEL PROVIDED TO THE ISSUER IN FORM,
SUBSTANCE AND SCOPE REASONABLY ACCEPTABLE TO THE ISSUER TO THE EFFECT THAT
REGISTRATION IS NOT REQUIRED UNDER THE LAWS DUE TO AN AVAILABLE EXCEPTION TO OR
EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE LAWS.

                             INTERCELL CORPORATION

                        WARRANT TO PURCHASE COMMON STOCK


                    Warrant No.4  Number of Shares:  66,667

                       Date of Issuance: December 3, 1997

     Intercell Corporation, a Colorado corporation (the "Company"), hereby
certifies that, for value received, FT Trading, and permitted assigns, the
registered holder hereof ("Holder"), is entitled, subject to the terms set forth
below, to purchase from the Company upon surrender of this Warrant, at any time
after the date hereof, but not after 5:00 p.m. Denver, Colorado time on the
Expiration Date (as defined herein) Sixty-Six Thousand Six Hundred Sixty-Seven
(66,667) fully paid and nonassessable shares of Common Stock (as defined herein)
of the Company (each a "Warrant Share" and collectively the "Warrant Shares") at
a purchase price of  U.S. $.17 per share (the "Exercise Price") in lawful money
of the United States. The number of Warrant Shares purchasable hereunder and the
Exercise Price are subject to adjustment as provided in Section 9 below.

     Section 1.

     (a) Definitions.  The following words and terms used in this Warrant shall
have the following meanings:

     "Common Stock" means (a) the Company's common stock and (b) any capital
stock into which such Common Stock shall have been changed or any capital stock
resulting from a reclassification of such Common Stock.

     "Convertible Securities" mean any securities issued by the Company which
are convertible into or exchangeable for, directly or indirectly, shares of
Common Stock.

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     "Expiration Date" means the date which is three (3) years from the date of
this Warrant or, if such date falls on a Saturday, Sunday or other day on which
banks are required or authorized to be closed in the City of Denver or the State
of Colorado (a "Holiday"), the next preceding date that is not a Holiday.

     "Market Price" means the closing bid price on the day prior to the date on
which the Exercise Form is delivered to the Company, as quoted on the National
Association of Securities Dealers' OTC Bulletin Board Market.

     "Securities Act" means the Securities Act of 1933, as amended.

     "Securities Purchase Agreement" shall mean the Securities Purchase
Agreement between the holder hereof (or its predecessor in interest) and the
Company for the purchase of this Warrant and the other Securities (as defined in
the Securities Purchase Agreement).

     "Transfer" shall include any disposition of this Warrant or any Warrant
Shares, or of any interest in either thereof which would constitute a sale
thereof within the meaning of the Securities Act of 1933, as amended, or
applicable state securities laws.

     "Warrant" shall mean this Warrant and all Warrants issued in exchange,
transfer or replacement of any thereof.

     "Warrant Exercise Price" shall be U.S. $.17 per share.

     (b) Other Definitional Provisions.

     (i) Except as otherwise specified herein, all references herein (A) to the
Company shall be deemed to include the Company's successors; and (B) to any
applicable law defined or referred to herein, shall be deemed references to such
applicable law as the same may have been or may be amended or supplemented from
time to time.

     (ii) When used in this Warrant, unless the otherwise specified in a
particular instance, the words "herein," "hereof," and "hereunder," and words of
similar import, shall refer to this Warrant as a whole and not to any provision
of this Warrant, and the words "Section," "Schedule," and "Exhibit" shall refer
to Sections of, and Schedules and Exhibits to, this Warrant unless otherwise
specified.

     (iii)  Whenever the context so requires the neuter gender includes the
masculine or feminine, and the singular number includes the plural, and vice
versa.

     Section 2.  Exercise of Warrant.

     (a) Subject to the terms and conditions hereof, this Warrant may be
exercised by the Holder, as a whole or in part, at any time prior to 5:00 p.m.
Denver, Colorado Time on the Expiration Date.  The rights represented by this
Warrant may be exercised by the Holder, as a whole or from time to time in part
(except that this Warrant shall not be exercisable as to a fractional share) by
(i) delivery of a written notice, in the form of the exercise form attached as
Exhibit I hereto (an "Exercise Form"), of the Holder's election to exercise this
Warrant, which notice shall specify the number of Warrant Shares to be
purchased, (ii) payment to the Company

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of an amount equal to the Warrant Exercise Price multiplied by the number of
Warrant Shares as to which the Warrant is being exercised (plus any applicable
issue or transfer taxes) in immediately available funds (either by wire transfer
or a certified or cashier's check drawn on a United States bank), for the number
of Warrant Shares as to which this Warrant shall have been exercised, and (iii)
the surrender of this Warrant, properly endorsed, at the principal office of the
Company (or at such other agency or office of the Company as the Company may
designate by notice to the Holder).

     In addition, and notwithstanding anything to the contrary contained in this
Warrant, this Warrant may be exercised by presentation and surrender of this
Warrant to the Company in a cashless exercise, including a written calculation
of the number of Warrant Shares to be issued upon such exercise in accordance
with the terms hereof (a "Cashless Exercise"). In the event of a Cashless
Exercise, in lieu of paying the Exercise Price, the Holder shall surrender this
Warrant for, and the Company shall issue in respect thereof, the number of
Warrant Shares determined by multiplying the number of Warrant Shares to which
the Holder would otherwise be entitled by a fraction, the numerator of which
shall be the difference between the then current Market Price per share of the
Common Stock and the Exercise Price, and the denominator of which shall be the
then current Market Price per share of Common Stock.

     The Warrant Shares so purchased shall be deemed to be issued to the Holder
or Holder's designees, as the record owner of such Warrant Shares, as of the
date on which this Warrant shall have been surrendered, the completed Exercise
Agreement shall have been delivered, and payment (or notice of an election to
effect a Cashless Exercise) shall have been made for such Warrant Shares as set
forth above.

     In the event of any exercise of the rights represented by this Warrant in
compliance with this Section 2(a), a certificate or certificates for the Warrant
Shares so purchased, registered in the name of, or as directed by, the Holder,
shall be delivered to, or as directed by, the Holder within three (3) business
days after such rights shall have been so exercised.

     (b) Unless this Warrant shall have expired or shall have been fully
exercised, the Company shall issue a new Warrant identical in all respects to
the Warrant exercised except (i) it shall represent rights to purchase the
number of Warrant Shares purchasable immediately prior to such exercise under
the Warrant exercised, less the number of Warrant Shares with respect to which
such Warrant is exercised, and (ii) the holder thereof shall be deemed to have
become the holder of record of such Warrant Shares immediately prior to the
close of business on the date on which the Warrant is surrendered and payment of
the amount due in respect of such exercise and any applicable taxes is made,
irrespective of the date of delivery of such share certificate, except that, if
the date of such surrender and payment is a date when the stock transfer books
of the Company are properly closed, such person shall be deemed to have become
the holder of such Warrant Shares at the opening of business on the next
succeeding date on which the stock transfer books are open.

     (c) In the case of any dispute with respect to an exercise, the Company
shall promptly issue such number of Warrant Shares as are not disputed in
accordance with this Section. If such dispute only involves the number of
Warrant Shares receivable by the Holder under a Cashless
Exercise, the Company shall submit the disputed calculations to an independent
accounting firm of national standing via facsimile within two (2) business days
of receipt of the Exercise Form. 

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The accountant shall audit the calculations and notify the Company and the
Holder of the results no later than two (2) business days from the date it
receives the disputed calculations. The accountant's calculation shall be deemed
conclusive absent manifest error. The Company shall then issue the appropriate
number of shares of Common Stock in accordance with this Section.

     Section 3.  Covenants as to Common Stock.  The Company covenants and agrees
that all Warrant Shares which may be issued upon the exercise of the rights
represented by this Warrant will, upon issuance, be validly issued, fully paid
and non-assessable.  The Company further covenants and agrees that during the
period within which the rights represented by this Warrant may be exercised, the
Company will at all times have authorized and reserved a sufficient number of
shares of Common Stock to provide for the exercise of the rights then
represented by this Warrant and that the par value of said shares will at all
times be less than or equal to the applicable Warrant Exercise Price.

     Section 4.  Taxes.  The Company shall not be required to pay any tax or
taxes attributable to the initial issuance of the Warrant Shares or any
permitted transfer involved in the issue or delivery of any certificates for
Warrant Shares in a name other than that of the registered holder hereof or upon
any permitted transfer of this Warrant.

     Section 5.  Warrant Holder Not Deemed a Stockholder.  No holder, as such,
of this Warrant shall be entitled to vote or receive dividends or be deemed the
holder of shares of the Company for any purpose, nor shall anything contained in
this Warrant be construed to confer upon the holder hereof, as such, any of the
rights of a stockholder of the Company or any right to vote, give or withhold
consent to any corporate action (whether any reorganization, issue of stock,
reclassification of stock, consolidation, merger, conveyance or otherwise),
receive notice of meetings, receive dividends or subscription rights, or
otherwise, prior to the issuance to the holder of this Warrant of the Warrant
Shares which he or she is then entitled to receive upon the due exercise of this
Warrant. Notwithstanding the foregoing, the Company will provide the holder of
this Warrant with copies of the same notices and other information given to the
stockholders of the Company generally, contemporaneously with the giving thereof
to the stockholders.

     Section 6.  No Limitation on Corporate Action.  No provisions of this
Warrant and no right or option granted or conferred hereunder shall in any way
limit, affect or abridge the exercise by the Company of any of its corporate
rights or powers to recapitalize, amend its Certificate of Incorporation,
reorganize, consolidate or merge with or into another corporation, or to
transfer all or any part of its property or assets, or the exercise of any other
of its corporate rights and powers.

     Section 7.  Representations of Holder.  The holder of this Warrant, by the
acceptance hereof, represents that it is acquiring this Warrant and the Warrant
Shares for its own account for investment and not with a view to, or for sale in
connection with, any distribution hereof or of any of the shares of Common Stock
or other securities issuable upon the exercise thereof, and not with any present
intention of distributing any of the same.  Upon exercise of this Warrant, the
holder shall, if requested by the Company, confirm in writing, in a form
satisfactory to the Company, that the Warrant Shares so purchased are being
acquired solely for the holder's own account and not as a nominee for any other
party, for investment, and not with a view toward distribution or resale. If
such holder cannot make such representations because they would be

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factually incorrect, it shall be a condition to such holder's exercise of the
Warrant that the Company receive such other representations as the Company
considers reasonably necessary to assure the Company that the issuance of its
securities upon exercise of the Warrant shall not violate any United States or
state securities laws.

     Section 8.  Transfer; Opinions of Counsel; Restrictive Legends.

     (a) The holder of this Warrant understands that (i) this Warrant and the
Warrant Shares have not been and are not being registered under the Securities
Act or any state securities laws (other than as described in the Securities
Purchase Agreement and the Registration Rights Agreement), and may not be
offered for sale, sold, assigned or transferred unless (a) subsequently
registered thereunder, or (b) pursuant to an exemption from such registration;
(ii) any sale of such securities made in reliance on Rule 144 promulgated under
the Securities Act may be made only in accordance with the terms of said Rule
and further, if said Rule is not applicable, any resale of such securities under
circumstances in which the seller (or the person through whom the sale is made)
may be deemed to be an underwriter (as that term is defined in the Securities
Act) may require compliance with some other exemption under the Securities Act
or the rules and regulations of the Securities and Exchange Commission
thereunder; and (iii) neither the Company nor any other person is under any
obligation to register such securities (other than as described in the
Securities Purchase Agreement and the Registration Rights Agreement) under the
Securities Act or any state securities laws or to comply with the terms and
conditions of any exemption thereunder.

     Section 9.  Adjustments.

     (a) Reclassification and Reorganization.  In case of any reclassification,
capital reorganization or other change of outstanding shares of the Common
Stock, or in case of any consolidation or merger of the Company with or into
another corporation (other than a consolidation or merger in which the Company
is the continuing corporation and which does not result in any reclassification,
capital reorganization or other change of outstanding shares of Common Stock),
the Company shall cause effective provision to be made so that the Holder shall
have the right thereafter, by exercising this Warrant, to purchase the kind and
number of shares of stock or other securities or property (including cash)
receivable upon such reclassification, capital reorganization or other change,
consolidation or merger by a holder of the number of shares of Common Stock that
could have been purchased upon exercise of the Warrant immediately prior to such
reclassification, capital reorganization or other change, consolidation or
merger. Any such provision shall include provision for adjustments that shall be
as nearly equivalent as may be practicable to the adjustments provided for in
this Section 9. The foregoing provisions shall similarly apply to successive
reclassifications, capital reorganizations and other changes of outstanding
shares of Common Stock and to successive consolidations or mergers. If the
consideration received by the holders of Common Stock is other than cash, the
value shall be as determined by the Board of Directors of the Company acting in
good faith.

     (b) Dividends and Stock Splits.  If and whenever the Company shall effect a
stock dividend, a stock split, a stock combination, or a reverse stock split of
the Common Stock, the number of Warrant Shares purchasable hereunder and the
Warrant Exercise Price shall be proportionately adjusted in the manner
determined by the Company's Board of Directors acting

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in good faith. The number of shares, as so adjusted, shall be rounded down to
the nearest whole number and the Warrant Exercise Price shall be rounded to the
nearest cent.

     Section 10.  Lost, Stolen, Mutilated or Destroyed Warrant.  If this Warrant
is lost, stolen or destroyed, the Company shall, on receipt of an
indemnification undertaking reasonably satisfactory to the Company, issue a new
Warrant of like denomination and tenor as the Warrant so lost, stolen or
destroyed. In the event the holder hereof asserts such loss, theft or
destruction of this Warrant, the Company may require such holder to post a bond
issued by a surety reasonably satisfactory to the Company with respect to the
issuance of such new Warrant.

     Section 11.  Notice.  Any notices required or permitted to be given under
the terms of this Warrant shall be sent by mail or delivered personally or by
courier and shall be effective five days after being placed in the mail, if
mailed, certified or registered, return receipt requested, or upon receipt, if
delivered personally or by courier or by facsimile, in each case properly
addressed to the party to receive the same.  The addresses for such
communications shall be:

  If to the Company:     Intercell Corporation
                         370 17th Street, Suite 3290
                         Denver, Colorado 80202
                         Telephone: 303-592-1010
                         Facsimile: 303-592-1054
                         Attention: Mr. Paul H. Metzinger, President & CEO

If to Holder, to it at the address set forth below Holder's signature on the
signature page of the Securities Purchase Agreement (Holder is defined therein
as the "Buyer").  Each party shall provide notice to the other party of any
change in address.

     Section 12.  Miscellaneous.  This Warrant and any term hereof may be
changed, waived, discharged, or terminated only by an instrument in writing
signed by the party or holder hereof against which enforcement of such change,
waiver, discharge or termination is sought.  The headings in this Warrant are
for convenience of reference only and shall not limit or otherwise affect the
meaning hereof.  This Warrant shall be governed by and interpreted under the
laws of the State of Colorado. Headings are for convenience only and shall not
affect the meaning or construction of any of the provisions hereof. This Warrant
shall be binding upon the Company and its successors and assigns and shall inure
to the benefit of  the Holder and its successors and assigns. The Holder may not
assign this Warrant except in accordance with applicable federal and state
securities laws. The Holder shall immediately notify the Company with respect to
any permitted assignment of this Warrant.

     Section 13.  Date.  The date of this Warrant is December 3, 1997.  This
Warrant, in all events, shall be wholly void and of no effect after the close of
business on the Expiration Date, except that notwithstanding any other
provisions hereof, the provisions of Section 8 shall continue in full force and
effect after such date as to any Warrant Shares or other securities issued upon
the exercise of this Warrant.

                            [SIGNATURE PAGE FOLLOWS]

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             [SIGNATURE PAGE TO WARRANT # 4 DATED DECEMBER 3, 1997]



                                    INTERCELL CORPORATION


                                    By /s/ Paul H. Metzinger
                                       --------------------------------------
                                           Paul H. Metzinger, President & CEO

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                              EXHIBIT I TO WARRANT


                        EXERCISE FORM TO BE EXECUTED BY
                 THE REGISTERED HOLDER TO EXERCISE THIS WARRANT

                             INTERCELL CORPORATION

     The undersigned hereby exercises the right to purchase the number of
Warrant Shares covered by the Warrant attached hereto as specified below
according to the conditions thereof and herewith makes payment of U.S.
$______________________ (unless effected by a Cashless Exercise in accordance
with the terms of the Warrant), the aggregate Warrant Exercise Price of such
Warrant Shares in full pursuant to the terms and conditions of the Warrant.

     (i)    The undersigned agrees not to offer, sell, transfer or otherwise
dispose of any Common Stock obtained upon exercise of the Warrant, except under
circumstances that will not result in a violation of the 1933 Act or applicable
state securities laws.
 
     (ii)   The undersigned requests that the stock certificates for the Warrant
Shares be issued, and a Warrant representing any unexercised portion hereof be
issued, pursuant to the terms of the Warrant in the name of the Holder (or such
other person(s) indicated below) and delivered to the undersigned (or
designee(s)) at the address or addresses set forth below.


Dated:______, 199_.

                                    HOLDER:_____________________________

                                    By:_________________________________
                                    Name:_______________________________
                                    Title:______________________________

 
                                    Address:

                                    ____________________________________
                                    ____________________________________
                                    ____________________________________
 

 
Number of Warrant Shares
Being Purchased:__________________

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