Exhibit 4.1

                              AMENDED AND RESTATED

                          CERTIFICATE OF INCORPORATION

                                       OF

                               APHTON CORPORATION

                                -----------------


          This  Amended  and  Restated   Certificate  of   Incorporation   (this
"Certificate  of  Incorporation")  has been  duly  adopted  in  accordance  with
Sections  242 and 245 of the  Delaware  General  Corporation  Law.  The original
certificate of incorporation  was filed with the Secretary of State of the State
of Delaware on October 30, 1997.

          First: The name of the Corporation is

                               Aphton Corporation

          Second:  The  registered  office  of the  Corporation  in the State of
Delaware is Corporation  Trust Center,  1209 Orange Street,  City of Wilmington,
County of New Castle, 19801,  Delaware.  The name of its registered agent in the
State of Delaware at such address is The Corporation Trust Company.

          Third:  The  purpose  of the  Corporation  is to engage,  directly  or
indirectly,  in any  lawful  act  or  activity  for  which  corporations  may be
organized  under the  General  Corporation  Law of the State of Delaware as from
time to time in effect.

          Fourth: The total authorized capital stock of the Corporation shall be
64,000,000 shares consisting of:

          1.  60,000,000 shares of Common Stock, par value $ 0.001; and

          2.  4,000,000 shares of Preferred Stock, par value $ 0.001.

          The Board of  Directors  is  authorized,  subject  to any  limitations
prescribed  by law, to provide for the issuance of shares of Preferred  Stock in
series and, by filing a certificate  pursuant to the applicable law of the State
of Delaware,  to establish from time to time the number of shares to be included
in each such series, and to fix the designation,  powers, preferences and rights
of the  shares  of each  such  series  and any  qualifications,  limitations  or
restrictions thereon.

          Fifth: The name and mailing address of the incorporator is as follows:

          Name                                     Mailing Address

<PAGE>

          Josh DeRienzis                           1155 Avenue of the Americas
                                                   New York, New York 10036

          Sixth: BOARD OF DIRECTORS

          1. The business of the  Corporation  shall be under the direction of a
Board of  Directors  except as  otherwise  provided  by law.  In addition to the
powers  and  authority  expressly  conferred  upon  them by  statute  or by this
Certificate of Incorporation or the Bylaws of the Corporation, the directors are
hereby  empowered to exercise all such powers and do all such acts and things as
may be exercised or done by the  Corporation.  Election of Directors need not be
by written ballot unless the Bylaws of the Corporation shall so provide.

          2.  Subject  to the rights of the  holders of any series of  Preferred
Stock to elect additional directors under specified circumstances, the number of
directors constituting the entire Board of Directors shall be fixed from time to
time exclusively by the Board of Directors pursuant to a resolution adopted by a
majority  of the  entire  Board of  Directors  (excluding,  for the  purpose  of
determining the number of directors constituting the entire Board, any vacancies
in the  Board  of  Directors).  Commencing  with  the  1998  Annual  Meeting  of
Stockholders  of the  Corporation,  the  directors,  other than those who may be
elected  by the  holders  of any  series  of  Preferred  Stock  under  specified
circumstances, shall be divided into three classes, as nearly equal in number as
possible,  with the term of  office  of the  first  class to  expire at the 1999
Annual Meeting of Stockholders, the term of office of the second class to expire
at the 2000 Annual Meeting of  Stockholders  and the term of office of the third
class to expire at the 2001 Annual Meeting of  Stockholders,  with each director
to hold office until such director's  successor shall have been duly elected and
qualified.  At each Annual  Meeting of  Stockholders,  commencing  with the 1999
Annual Meeting of Stockholders, (i) Directors elected to succeed those directors
whose terms  expire shall be elected for a term of office to expire at the third
succeeding  Annual  Meeting of  Stockholders  after their  election  and (ii) if
authorized by a resolution  of the Board of Directors,  directors may be elected
to fill any vacancy on the Board of  Directors,  regardless  of how such vacancy
shall have been created.

          3.  Subject  to the rights of the  holders of any series of  Preferred
Stock then outstanding,  and unless the Board of Directors otherwise determines,
newly created directorships resulting from any increase in the authorized number
of directors or any  vacancies in the Board of Directors  resulting  from death,
disability, resignation,  retirement,  disqualification,  removal from office or
other  cause shall be filled only by a majority  vote of the  directors  then in
office, though less than a quorum, and directors so chosen shall hold office for
a term  expiring  at the  Annual  Meeting of  Stockholders  at which the term of
office of the  class to which  they have been  elected  expires  and until  such
director's  successor shall have been duly elected or qualified.  No decrease in
the number of directors  constituting  the Board of Directors  shall shorten the
term of any incumbent director.

          4.  Subject  to the rights of the  holders of any series of  Preferred
Stock then outstanding,  any director, or the entire Board of Directors,  may be
removed from office at any time, but only for cause.

                                      -2-

<PAGE>

          5.  Notwithstanding  any  other  provisions  of  this  Certificate  of
Incorporation or any provision of law which might otherwise permit a lesser vote
or no vote,  but in  addition  to any  affirmative  vote of the  holders  of any
particular  class  or  series  of  the  capital  stock  required  by  law,  this
Certificate of  Incorporation  or any series of Preferred Stock, the affirmative
vote of the  holders of at least 80  percent  of the voting  power of all of the
then-outstanding  shares of the capital stock  entitled to vote for the election
of directors,  voting  together as a single  class,  shall be required to alter,
amend or repeal this Article SIXTH.

          SEVENTH:  Subject  to the  rights  of the  holders  of any  series  of
Preferred  Stock,  (A) any  action  required  or  permitted  to be  taken by the
stockholders of the Corporation must be effected at an annual or special meeting
of  stockholders  of the  Corporation  and may not be effected by any consent in
writing by such  stockholders  and (B) special  meetings of  stockholders of the
Corporation  may be called only by the Chairman of the Board of  Directors,  the
President  or by the Board of Directors  pursuant to a  resolution  adopted by a
majority of the entire Board of Directors.  Notwithstanding any other provisions
of this  Certificate  of  Incorporation  or any  provision  of law  which  might
otherwise  permit a lesser vote or no vote,  but in addition to any  affirmative
vote of the holders of any  particular  class or series of the capital  stock of
the Corporation required by law, this Certificate of Incorporation or any series
of Preferred  Stock,  the affirmative vote of the holders of at least 80 percent
of the  voting  power of all of the  then-outstanding  shares of  capital  stock
entitled to vote for the  election  of  directors,  voting  together as a single
class, shall be required to alter, amend or repeal this Article SEVENTH.

          EIGHTH: The Board of Directors may make, alter or repeal the Bylaws of
the Corporation  subject to the power of the holders of the capital stock of the
Corporation to alter, amend or repeal the Bylaws.

          NINTH:  The  Directors  of the  Corporation  shall be  protected  from
personal liability,  through indemnification or otherwise, to the fullest extent
permitted  under the  General  Corporation  Law of the State of Delaware as from
time to time in effect.

          1. A Director of the Corporation shall under no circumstances have any
personal  liability to the Corporation or its  stockholders for monetary damages
for breach of fiduciary duty as a Director except for those breaches and acts or
omissions  with  respect to which the  General  Corporation  Law of the State of
Delaware,  as from time to time amended,  expressly provides that this provision
shall not eliminate or limit such personal  liability of Directors.  Neither the
modification or repeal of this paragraph 1 of Article NINTH nor any amendment to
said General  Corporation Law that does not have retroactive  application  shall
limit the right of Directors  hereunder to exculpation  from personal  liability
for any act or  omission  occurring  prior to such  amendment,  modification  or
repeal.

          2. Each person who was or is made a party or is  threatened to be made
a party to or is involved  in any action,  suit or  proceeding,  whether  civil,
criminal,  administrative  or  investigative  (hereinafter a  "proceeding"),  by
reason  of the fact  that he or she,  or a person of whom he or she is the legal
representative, is or was a director or officer, of the Corporation or is or was
serving at the request of the  Corporation as a director,  officer,  employee or
agent of another Corporation or of a partnership,  joint venture, trust or other
enterprise,  including  service with respect to employee benefit plans,  whether
the basis of such  proceeding  is alleged  action in

                                      -3-

<PAGE>

an official capacity as a director,  officer,  employee or agent or in any other
capacity  while  serving as a director,  officer,  employee  or agent,  shall be
indemnified  and  held  harmless  by  the  Corporation  to  the  fullest  extent
authorized by the Delaware  General  Corporation  Law, as the same exists or may
hereafter be amended (but, in the case of any such amendment, only to the extent
that such amendment  permits the Corporation to provide broader  indemnification
rights  than  said  law  permitted  the  Corporation  to  provide  prior to such
amendments,  against all expense, liability and loss (including attorneys' fees,
judgments, fines, ERISA excise taxes or penalties and amounts paid or to be paid
in  settlement)  reasonably  incurred or  suffered by such person in  connection
therewith and such indemnification  shall continue as to a person who has ceased
to be a director,  officer,  employee or agent and shall inure to the benefit of
his or her heirs, executors and administrators;  provided, however, that, except
as provided in paragraph (b) hereof,  the  Corporation  shall indemnify any such
person seeking indemnification in connection with a proceeding (or part thereof)
initiated  by  such  person  only if  such  proceeding  (or  part  thereof)  was
authorized by the Board of Directors. The right to indemnification  conferred in
this Bylaw shall be a contract  right and shall  include the right to be paid by
the  Corporation  the expenses  incurred in  defending  any such  proceeding  in
advance of its final  disposition;  provided,  however,  that,  if the  Delaware
General  Corporation  Law requires,  the payment of such expenses  incurred by a
Director or officer in his or her  capacity as a Director or officer (and not in
any other  capacity in which  service was or is rendered by such person  while a
Director  or  officer,  including  without  limitation,  service to an  employee
benefit plan) in advance of the final disposition of a proceeding, shall be made
only upon delivery to the Corporation of an undertaking, by or on behalf of such
Director or officer,  to repay all amounts so advanced if it shall ultimately be
determined that such Director or officer is not entitled to he indemnified under
this  Bylaw or  otherwise.  The  Corporation  may,  by  action  of its  Board of
Directors,  provide  indemnification  to employees and agents of the Corporation
with the same scope and effect as the foregoing indemnification of Directors and
officers.

          3. If a claim under paragraph (a) of this Bylaw is not paid in full by
the  Corporation  within  thirty days after a written claim has been received by
the Corporation,  the claimant may at any time thereafter bring suit against the
Corporation  to recover  the unpaid  amount of the claim and, if  successful  in
whole or in part,  the claimant shall be entitled to be paid also the expense of
prosecuting  such claim. It shall be a defense to any such action (other than an
action  brought  to  enforce a claim for  expenses  incurred  in  defending  any
proceeding in advance of its final disposition  where the required  undertaking,
if any is required,  has been tendered to the Corporation) that the claimant has
not met the  standards of conduct which make it  permissible  under the Delaware
General  Corporation  Law for the  Corporation to indemnify the claimant for the
amount  claimed,  but  the  burden  of  proving  such  defense  shall  be on the
Corporation.  Neither the  failure of the  Corporation  (including  its Board of
Directors,  independent  legal  counsel,  or its  stockholders)  to have  made a
determination  prior to the commencement of such action that  indemnification of
the  claimant  is  proper  in the  circumstances  because  he or she has met the
applicable  standard of conduct set forth in the  Delaware  General  Corporation
Law, nor an actual  determination  by the  Corporation  (including  its Board of
Directors, independent legal counsel, or its stockholders) that the claimant has
not met such applicable standard of conduct, shall be a defense to the action or
create a presumption  that the claimant has not met the  applicable  standard of
conduct.

                                      -4-

<PAGE>

          4. The right to  indemnification  and the payment of expenses incurred
in defending a proceeding in advance of its final disposition  conferred in this
Bylaw  shall not be  exclusive  of any other  right which any person may have or
hereafter   acquire  under  any  statute,   provision  of  the   Certificate  of
Incorporation, Bylaw, agreement, vote of stockholders or disinterested directors
or otherwise.

          5. The Corporation may maintain insurance,  at its expense, to protect
itself  and any  director,  officer,  employee  or agent of the  Corporation  or
another  Corporation,  partnership,  joint  venture,  trust or other  enterprise
against any such  expense,  liability  or loss,  whether or not the  Corporation
would have the power to indemnify such person against such expense, liability or
loss under the Delaware General Corporation Law.

                                      -5-

<PAGE>


          I, THE UNDERSIGNED, being an authorized officer of the Corporation, do
make this amended and restated certificate, hereby declaring and certifying that
this is my act and deed and that the  facts  herein  stated  are true and that I
have accordingly hereunto signed my signature this 21st day of May, 2003.

                                    /s/ Philip C. Gevas
                                --------------------------------------------
                                Philip C. Gevas
                                Chairman, President and Chief Executive Officer