<PAGE>   1
                                             CONFIDENTIAL MATERIAL OMITTED
                                             AND FILED SEPARATELY WITH THE
                                             SECURITIES AND EXCHANGE COMMISSION.
                                             ASTERISKS DENOTE SUCH OMISSIONS.




                                                                 EXHIBIT 10.28
                 ----------------------------------------------

                           VIBRIOVEC LICENSE AGREEMENT

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


This Agreement is entered as of this 1st day of December, 1997 (the "EFFECTIVE
DATE") into BY AND AMONG:

         VIRUS RESEARCH INSTITUTE, INC., a company organized and existing under
         the laws of the State of Delaware, having its principal place of
         business at 61, Moulton Street, Cambridge, Massachusetts, USA,

         (hereinafter referred to as "VRI")

AND

         MERIEUX ORAVAX S.N.C., a societe en nom collectif organized and
         existing under the laws of the Republic of France, registered at the
         Registre du Commerce et des Societes in Lyon under No. RCS Lyon B 404
         337 172, with a capital of 52.000.000 French Francs, whose registered
         head-office is located at 58, avenue Leclerc, 69007 Lyon, France,

         ORAVAX MERIEUX CO., a general partnership organized and existing under
         the laws of the State of Massachussetts, having its principal place of
         business at 38, Sidney Street, Cambridge, Massachussetts, USA,

         (the parties numbered and above are individually and collectively
         hereinafter referred to as "LICENSEE" or "HPC")

                                   WITNESSETH

WHEREAS, VRI has developed certain confidential and/or proprietary information,
patents and patent applications and material relating to a vaccine delivery
system that uses an attenuated form of Vibrio cholerae as a vector for the oral
delivery of antigens ("VIBRIOVEC") which may present an interest in connection
with vaccination against, and immunotherapy of, Helicobacter pylori infections;

WHEREAS, HPC are joint venture entities created and equally owned and controlled
by OraVax, Inc. of Cambridge, Massachussetts, USA, ("ORAVAX") and Pasteur
Merieux Serums & Vaccins S.A. -a Pasteur Merieux Connaught company- of Lyon,
France ("PMC") for the purpose of researching, developing, manufacturing and
distributing products for active immunization against Helicobacter pylori
infections and prevention, treatment and cure of associated diseases and
conditions in humans;

WHEREAS, HPC wishes to acquire from VRI certain licenses in order to have the
right to use VibrioVec in connection with vaccines against Helicobacter pylori
infections, and VRI is willing to grant such licenses to HPC, subject to the
terms of and conditioned upon this Agreement;



                                       1
<PAGE>   2


NOW, THEREFORE, in consideration of the premises herein and for other good and
valuable consideration, the Parties hereto, intending to be legally bound, agree
as follows:


ARTICLE 1 - DEFINITIONS AND INTERPRETATION

1.1.     DEFINITIONS: For the purposes of this Agreement the following words
         and phrases shall have the following meanings:

         (a)      "AFFILIATE" means, with respect to any Person, (i) any other
                  Person of which the securities or other ownership interests
                  representing fifty per cent (50 %) or more of the equity or
                  fifty per cent (50%) or more of the ordinary voting power or
                  fifty per cent (50%) or more of the general partnership
                  interest are, at the time such determination is being made,
                  owned, Controlled or held, directly or indirectly, by such
                  Person (a "SUBSIDIARY"), or (ii) any other Person which, at
                  the time such determination is being made, is Controlling, or
                  under common Control with, such Person. As used herein, the
                  term "Control", whether used as a noun or verb, refers to the
                  possession, directly or indirectly, of the power to direct, or
                  cause the direction of, the management or policies of a
                  Person, whether through the ownership of voting securities, by
                  contract or otherwise. For the avoidance of doubt, it is
                  hereby recorded that, notwithstanding the definition contained
                  in this Section 1.1.(a), the two HPC entities are Affiliates
                  of both OraVax and PMC and of each other, and that OraVax and
                  PMC are each Affiliates of the two HPC entities.

         (b)      "AGREEMENT" means this agreement, all amendments and
                  supplements to this Agreement and all schedules to this
                  Agreement, including the following:

                  SCHEDULE A - LICENSED PATENTS,
                  SCHEDULE B - List of HPC Antigens.
                  APPENDIX A - Terms and conditions applicable to research
                               contract.
                  APPENDIX B - Terms and conditions applicable to VECTOR supply.

         (c)      "CALENDAR QUARTER" means any of the three-month periods
                  beginning January 1, April 1, July 1 and October 1 in any
                  year.

         (d)      "VECTOR" means a vaccine delivery system that uses an
                  attenuated form of the bacterium Vibrio cholerae as a vector
                  for the oral delivery of antigens, known as VibrioVec;

         (e)      "VECTOR IMPROVEMENTS" means all patentable or non-patentable
                  inventions, discoveries, technology and information of any
                  type whatsoever, which add to the knowledge of the VECTOR or
                  its properties in general as a delivery system or an
                  immunoadjuvant, as the case may be, for use in the Field of
                  Use, including without limitation compositions, molecules
                  derived from VECTOR, methods, processes, technical
                  information, knowledge, experience and know-how.

         (f)      "CONFIDENTIAL INFORMATION" has the meaning ascribed to it in
                  Section 8.1. of this Agreement.



                                       2
<PAGE>   3

         (g)      "EVENT OF FORCE MAJEURE" has the meaning ascribed to it in
                  Article 12 of this Agreement.

         (h)      "FIELD OF USE" means the use of VRI Technology for the
                  formulation of products for active immunization against
                  Helicobacter pylori infections in humans and, by such
                  immunization, the prevention, treatment and cure of associated
                  diseases and conditions.

         (i)      "FIRST COMMERCIAL SALE" means, in each country of the
                  Territory, the first sale of a PRODUCT in commercial
                  quantities by LICENSEE, its Affiliates or Sublicensees, to
                  Third-Parties, in each case for use or consumption of such
                  PRODUCT in such country by the general public.

         (ii)     "JOINT INVENTIONS" has the meaning ascribed to it in Section
                  9.1 hereof.

         (j)      "LICENSE" has the meaning ascribed to it in Section 2.1.1. of
                  this Agreement.

         (k)      "LICENSED KNOW-HOW" means any and all technical information,
                  discoveries, improvements, processes, formulae, data,
                  engineering, technical and shop drawings, inventions,
                  Materials, shop-rights, know-how and trade secrets, in each
                  case which is Confidential Information at the time of
                  disclosure according to Article 8, is identified in accordance
                  with Section 2.3.3. of this Agreement as related to VECTOR and
                  which is useful or necessary to make, have made, use or sell
                  PRODUCTS or to practice under the LICENSED PATENTS in the
                  Field of Use, which have been, or hereafter are, either
                  developed by VRI or its Affiliates, or the rights to which in
                  the Field of Use have been acquired by VRI or its Affiliates
                  and to which VRI or its Affiliates have a transferable
                  interest. Without prejudice to the generality of the
                  foregoing, LICENSED KNOW-HOW shall include, with respect to
                  VECTOR, chemical and analytical methods and data, VECTOR
                  specifications, and pharmacological and toxicological methods
                  and data.

         (l)      "LICENSED PATENTS" means:

                  (i)      any existing patents and patent applications listed
                           in SCHEDULE A to this Agreement;

                  (ii)     any future patents issued from any patent
                           applications referred to in Paragraph 1.1.(l).(i)
                           above and any future patents issued from a patent
                           application filed in any country in the Territory
                           which corresponds to a patent or patent application
                           identified in Paragraph 1.1.(l).(i) above;

                  (iii)    any reissues, confirmations, renewals, extensions,
                           counterparts, divisions or continuations issued,
                           assigned or licensed to VRI or its Affiliates of or
                           relating to the patents or patent applications
                           identified in Paragraph 1.1.(l).(i) and (ii) above;

                  (iv)     any future patents and patent applications covering
                           VRI VECTOR Improvements solely or jointly owned or
                           licensed by VRI or its Affiliates with the right to
                           sublicense.

         (m)      "LICENSEE VECTOR IMPROVEMENTS" means VECTOR Improvements which
                  are conceived, developed or reduced to practice during the
                  term of this Agreement solely or jointly by employees or
                  contractors acting on behalf of LICENSEE, its Affiliates or
                  Sublicensees, to the extent and only to the extent that
                  LICENSEE now has or hereafter shall have the right to grant
                  licenses,



                                       3
<PAGE>   4
                  immunities or other rights thereon. For avoidance of doubt,
                  any technology developed by LICENSEE during the term and
                  pursuant to this Agreement which relates to any HPC Antigen or
                  Other Hp Antigen (rather than antigens in general), or to the
                  combination of such specific antigen with VECTOR, or to the
                  manufacturing of PRODUCTS shall not be included in LICENSEE
                  VECTOR Improvements. LICENSEE VECTOR Improvements shall be
                  deemed to include LICENSEE's interest in any Joint Inventions.

         (mm)     "LPS" means Helicobacter pylori antigens which are
                  lipopolysaccharides.

         (n)      "MANUFACTURING KNOW-HOW" means any and all technical
                  information, discoveries, improvements, processes, formulae,
                  data, engineering, technical and shop drawings, inventions,
                  shop-rights, know-how and trade secrets, in each case which is
                  Confidential Information at the time of disclosure in the
                  meaning of Article 8 hereof, is identified in accordance with
                  Section 2.3.3., which is owned or otherwise possessed by VRI
                  or VRI's Affiliates and to which VRI or its Affiliates have a
                  transferable interest, and which is useful or necessary to
                  make and have made VECTOR or to use VECTOR for the formulation
                  of PRODUCTS or to practice under the LICENSED PATENTS to the
                  extent such Patents relates to the manufacturing of VECTOR ;
                  in particular, but without limiting the generality of the
                  foregoing, Manufacturing Know-How shall include any and all
                  information regarding the synthesis, manufacture, up-scaling
                  and handling of VECTOR, any and all analytical procedures,
                  procedures for and specifications of quality-assurance and
                  quality-control.

         (o)      "MATERIALS" shall mean any biological materials and chemical
                  VECTOR including but not limited to structural genes, genetic
                  sequences, promoters, enhancers, probes, linkage probes,
                  vectors, hosts, plasmids, peptides, polypeptides, transformed
                  cell lines, transgenic animals, proteins, biological
                  modifiers, antigens, reagents, hybridomas, antibodies, toxins,
                  lectins, enzymes, lipids, hormones, viruses, cells or parts of
                  cells, cell lines, fragments of any of the foregoing and any
                  other biologically active material or VECTOR, whether or not
                  occurring naturally or howsoever derived, modified,
                  conjugated, cross-linked, immobilized, reduced, purified or
                  produced, whether by recombinant DNA techniques and/or
                  otherwise.

         (p)      "NET SALES" shall mean gross sales of PRODUCTS sold by
                  LICENSEE, its Affiliates and Sublicensees to Third-Parties
                  (including unaffiliated Third-Party distributors, except in
                  the circumstances referred to in Section 6.3 hereof, and
                  provided further that where a distributor is an Affiliate, but
                  neither a Subsidiary of LICENSEE nor a Subsidiary of OraVax or
                  PMC (other than HPC), such distributor shall be deemed a
                  Third-Party for the purpose of calculating Net Sales
                  hereunder) less, to the extent actually incurred or allowed:

                  (i)      customary trade discounts, credits, rebates, returns
                           (including, but not limited to, wholesaler and
                           retailer returns);

                  (ii)     excise taxes, other consumption taxes, customs duties
                           and compulsory payments made to governmental
                           authorities;

                  (iii)    transportation, transit and insurance for
                           transportation each to the extent separately invoiced
                           and paid by LICENSEE.

         (q)      "NOTICE OF DISPUTE" has the meaning ascribed to it in Section
                  17.4.(a) of this Agreement.




                                       4
<PAGE>   5

         (r)      "OTHER HP ANTIGENS" means any antigens of Helicobacter pylori
                  and genes encoding such antigens other than HPC Antigens and
                  LPS.

         (s)      "PARTIES" means LICENSEE and VRI, and "Party" means any one of
                  them.

         (t)      "PERSON" means an individual, corporation, partnership, trust,
                  business trust, association, joint stock company, pool,
                  syndicate, sole proprietorship, unincorporated organization,
                  governmental authority or any other form of entity not
                  specifically listed herein.

         (u)      "PHASE III" means the first large scale safety and efficacy
                  clinical trial relating to a PRODUCT.

         (v)      "PLA" means a product license application filed with the
                  European Medicines Evaluation Agency or its successor in the
                  European Union, or any analogous or corresponding application
                  filed with the governing health authority of any country or
                  region (such as the Food and Drug Administration in the United
                  States of America or the Agence du Medicament in France), for
                  approval to market any PRODUCT for use or consumption in such
                  country or region.

         (vv)     "HPC ANTIGENS" means antigens of Helicobacter pylori (other
                  than LPS), and genes encoding such antigens, which are listed
                  in SCHEDULE B as being included in LICENSEE's research &
                  development program, which list may be amended from time to
                  time by written notice by LICENSEE to VRI (i) to add antigens
                  which are included in LICENSEE's research & development
                  program, in which case such antigens shall then become HPC
                  Antigens and be treated as such for the purpose of this
                  Agreement, PROVIDED, HOWEVER, that VRI has not previously
                  granted a non-exclusive license to a Third-Party with respect
                  to the use of VECTOR in combination with such antigens, or
                  (ii) to delete antigens which are excluded from such program,
                  in which case such antigens shall become Other Hp Antigens and
                  be treated as such for the purpose of this Agreement;

         (w)      "PRODUCTS" means any and all vaccines for active immunization
                  intended for use in the Field of Use which contain HPC
                  Antigens (either alone, combined with each other or combined
                  with Other Hp Antigens) or Other Hp Antigens (either alone or
                  combined with each other), in each case formulated in
                  combination with VECTOR.

         (ww)     "RESEARCH INVENTIONS" has the meaning ascribed to it in
                  Section 9.1 hereof which refers to Section 9 of APPENDIX A to
                  this Agreement.

         (x)      "ROYALTY TERM" means, with respect to each PRODUCT in each
                  country in the Territory, the period of time equal to the
                  longer of (a) ten (10) years from the date of First Commercial
                  Sale of such PRODUCT in such country or (b) the term for which
                  a Valid Patent Claim in such country remains in effect and,
                  but for a license granted by this Agreement, would be
                  infringed by the manufacture, use or sale of such PRODUCT in
                  the Field of Use in such country.

         (xx)     "SUBLICENSEE" means any Person acting pursuant to a sublicense
                  granted to it by LICENSEE under the terms of this Agreement.

         (xxx)    "TERRITORY" means all countries in the world.

         (y)      "THIRD-PARTY" means any Person other than LICENSEE, VRI and
                  their respective Affiliates.




                                       5
<PAGE>   6

         (yy)     "VALID PATENT CLAIM" means a claim of an issued and unexpired
                  patent or patent application included in LICENSED PATENTS
                  which has not been held permanently revoked, unenforceable or
                  invalid by a decision of a court or other governmental agency
                  of competent jurisdiction, unappealable or unappealed within
                  the time allowed for appeal, and which has not been admitted
                  to be invalid or unenforceable through reissue or disclaimer
                  or otherwise.

         (z)      "VRI VECTOR IMPROVEMENTS" means VECTOR Improvements which are
                  conceived, developed or reduced to practice during the term of
                  this Agreement solely or jointly by employees or contractors
                  acting on behalf of VRI or its Affiliates, to the extent that
                  VRI has now or hereafter shall have the right to grant
                  licenses, immunities or other rights thereon. VRI VECTOR
                  Improvements shall be deemed to include VRI's interest in any
                  Joint Inventions.

         (zz)     "VRI TECHNOLOGY" means the LICENSED PATENTS, the VECTOR, the
                  Manufacturing Know-How, the LICENSED KNOW-HOW and the VRI
                  VECTOR Improvements.

ARTICLE 2 - LICENSES

2.1.     GRANT OF LICENSES TO LICENSEE

2.1.1.   GRANT:

         Subject to and conditioned upon the provisions of this Agreement, VRI
         hereby grants to LICENSEE, and LICENSEE hereby accepts, the following
         licenses (collectively, the "LICENSE"):

         (i)      a license in the Territory to make, have made, use and sell
                  PRODUCTS under the LICENSED PATENTS and by using LICENSED
                  KNOW-HOW and VRI VECTOR Improvements; and

         (ii)     a license in the Territory to make, have made and use the
                  VECTOR under the LICENSED PATENTS, and by using the
                  Manufacturing Know-How and VRI VECTOR Improvements, in each
                  case solely for the purpose of formulating PRODUCTS in the
                  Field of Use.

2.1.2.   EXCLUSIVITY

         (i)      HPC ANTIGENS. Subject to and conditioned upon the provisions
                  of this Agreement, the LICENSE granted pursuant to this
                  Article II shall be exclusive (exclusive even as to VRI) to
                  LICENSEE in the Field of Use with respect to PRODUCTS
                  combining any VECTOR with any HPC Antigens (either alone,
                  combined with each other or combined with Other Hp Antigens).
                  Without limiting the generality of the foregoing, VRI
                  covenants that during the term of this Agreement, neither VRI
                  nor its Affiliates shall grant to any other Person any right,
                  license or privilege to make, have made, use or sell PRODUCTS
                  containing HPC Antigens (alone, or in combination with each
                  other, or in combination with Other Hp Antigens), or to make,
                  have made or use VECTOR,




                                       6
<PAGE>   7

                  or to otherwise use or exploit VRI Technology, in connection
                  with such PRODUCTS containing HPC Antigens (alone, or in
                  combination with each other, or in combination with Other Hp
                  Antigens).

         (ii)     OTHER HP ANTIGENS. Subject to and conditioned upon the
                  provisions of this Agreement, the LICENSE granted pursuant to
                  this Article II shall be non-exclusive to LICENSEE in the
                  Field of Use with respect to PRODUCTS combining any VECTOR
                  with any Other Hp Antigens (alone or combined with each
                  other), but only with such Other Hp Antigens. Such license
                  shall be non-transferable and non-sub-licensable.

         (iii)    For greater certainty, VRI has and retains all rights in and
                  to the VRI Technology outside the Field of Use and LICENSEE
                  has no rights in the VRI Technology outside the Field of Use.
                  Further, the LICENSE shall not apply to nor cover any
                  combination of an Helicobacter pylori vaccine with any other
                  vaccine, or any Helicobacter pylori vaccine containing LPS.

2.1.3.   LICENSEE'S RIGHTS TO SUBLICENSE

         (i)      LICENSEE shall have the right, with VRI's prior written
                  consent (which consent shall not be unreasonably withheld), to
                  sublicense in the Field of Use to Third-Parties all or any
                  portion of the rights to LICENSED PATENTS and LICENSED
                  KNOW-HOW and VRI VECTOR Improvements granted to it pursuant to
                  this Agreement under the exclusive LICENSE.

         (ii)     LICENSEE shall have the right, without obtaining the further
                  consent of VRI, to sublicense in the Field of Use all or any
                  portion of the rights to the LICENSED PATENTS, the LICENSED
                  KNOW-HOW, VRI VECTOR Improvements and/or the Manufacturing
                  Know-How granted to it pursuant to this Agreement under both
                  the exclusive and the non-exclusive LICENSE (i) to any or all
                  of its Affiliates, and (ii) to any Person in any country of
                  the Territory if required to do so by any governmental
                  authority having jurisdiction in such country.

         (iii)    LICENSEE agrees that all sublicenses granted by LICENSEE
                  hereunder shall expressly bind Sublicensees to the terms of
                  Article 8, "Confidentiality" and to all other relevant
                  provisions of this Agreement. In the event LICENSEE grants
                  sublicenses, LICENSEE shall pay royalties to VRI as if Net
                  Sales of the Sublicensees were Net Sales of LICENSEE and VRI
                  shall be expressly made a third-party beneficiary thereof.
                  LICENSEE shall be responsible for the performance by any
                  Sub-licensee of all such terms, conditions and obligations.

         (iv)     Any sublicenses granted by LICENSEE shall include a
                  requirement that the Sublicensee maintains records and permits
                  inspection on terms essentially identical to Section 5.2
                  hereof. At VRI's request, LICENSEE shall arrange for an
                  independent certified public accountant selected by VRI to
                  inspect the records of Sublicensees, at VRI's expense, for the
                  purpose of verifying royalties due to VRI and shall cause such
                  accountant to report the results thereof to VRI.

         (v)      Any sublicenses granted by LICENSEE shall provide for the
                  termination of the sublicense, or, if the Sublicensee is a
                  Third-Party, at the option of such Sublicensee, the conversion
                  to a license directly between such Sublicensee and VRI, upon
                  termination of this Agreement under Article 10 (other than
                  expiration under Section 10.1). Such conversion shall be
                  subject to VRI's




                                       7
<PAGE>   8

                  approval and contingent upon acceptance by the Sublicensee of
                  the remaining provisions of this Agreement.

         (vi)     LICENSEE shall notify VRI of each sublicense granted to
                  Third-Parties and shall provide VRI with the name and address
                  of each Sublicensee and a description of the PRODUCTS and
                  territory covered by each sublicenses.

2.1.4.   SUBLICENSES TO LICENSEE.

         To the extent LICENSED PATENTS have been, or shall be, licensed by VRI
         from a Third-Party under an agreement with such Third-Party (a
         "Third-Party In-license"), HPC understands and agrees as follows:

         (i)-     The rights sub-licensed to HPC by VRI are subject to the terms
                  and conditions, restrictions, limitations and obligations of
                  the relevant Third-Party In-license;

         (ii)-    HPC shall comply with the terms and conditions, restrictions,
                  limitations and obligations of such Third-Party In-license(s)
                  to the extent HPC has been permitted to review such terms,
                  conditions, restrictions, limitations and obligations. VRI
                  shall give HPC, upon request, a reasonable opportunity to
                  review the same except to the extent that confidentiality
                  obligations towards Third-Parties may prevent VRI from doing
                  so. In any event, VRI shall act reasonably in advising HPC of
                  the scope of HPC's obligations pursuant to any relevant
                  Third-Party In-license.

2.1.5    SUBCONTRACTING.

         Notwithstanding anything herein provided for to the contrary, LICENSEE
         shall be allowed to (i) sub-contract in whole or in part PRODUCTS
         development to Third-Parties such as, without limitation, clinical
         research organizations, (ii) appoint sales agents and distributors to
         promote, market and distribute PRODUCTS and (iii) sub-contract
         manufacturing of PRODUCTS and/or VECTOR with Affiliates, Third-Parties
         or with VRI, or VRI's Affiliates.

2.2.     LICENSES TO VRI.

         Subject to and conditional upon the provisions of this Agreement,
         LICENSEE shall grant to VRI a non-exclusive, sublicenseable,
         royalty-free, worldwide license to LICENSEE VECTOR Improvements for
         commercial use outside the Field of Use.

2.3.     PROCEDURES FOR PROVISION OF KNOW-HOW.

2.3.1.   DISCLOSURE OF TECHNOLOGY.

         (a)      BY VRI.

                  From time to time during the term of this Agreement, VRI shall
                  disclose or cause its Affiliates to disclose to LICENSEE such
                  VRI Technology as reasonably necessary to enable LICENSEE to
                  develop, manufacture and commercialize PRODUCTS and to
                  manufacture, have manufactured or use VECTOR for the
                  formulation of PRODUCTS in the Field of Use on the terms





                                       8
<PAGE>   9

                  and subject to the conditions of this Agreement. In addition,
                  during the term of this Agreement, VRI shall, upon LICENSEE's
                  reasonable request and with adequate notice to VRI, make
                  available to LICENSEE at LICENSEE's or its Affiliates'
                  manufacturing facilities or the facility of a Third-Party
                  manufacturer who shall have contracted with LICENSEE to
                  manufacture PRODUCTS or VECTOR, VRI's or VRI Affiliate's
                  personnel to provide technical assistance to LICENSEE's
                  personnel, or LICENSEE Affiliates' personnel or Third-Party
                  manufacturer's personnel.

                  LICENSEE shall pay or have paid by its concerned Affiliates
                  all expenses incurred by VRI or its Affiliates in connection
                  with such technical assistance.

                  The technical assistance to be rendered by VRI and its
                  Affiliates hereunder may include, upon reasonable request by
                  LICENSEE, demonstration of Manufacturing Know-How at a VRI's
                  or a VRI Affiliate's facility and disclosure of any and all
                  sources of raw material and list and specifications of
                  equipment and machinery used in the production of VECTOR
                  according to the Manufacturing Know-How.

         (b)      BY LICENSEE.

                  From time to time during the term of this Agreement, LICENSEE
                  shall disclose to VRI all LICENSEE VECTOR Improvements on the
                  terms and subject to the conditions of the Agreement and in
                  particular in accordance with Section 2.2. hereof.

2.3.2.   COMMUNICATION AMONG PARTIES.

         Each of LICENSEE and VRI shall appoint (a) specific individual(s) who
         shall be available and shall act as (a) liaison person(s) to facilitate
         the day-to-day communications among the Parties. The names and
         addresses of the liaison persons who shall act on behalf of each of the
         Parties shall be provided by each of the Parties to the other
         immediately following the execution of this Agreement. Each of LICENSEE
         and VRI agrees to notify the other in accordance with the terms of
         Section 17.1. of this Agreement in the event of a change in liaison
         person.

2.3.3.   IDENTIFICATION OF KNOW-HOW.

         The Parties agree that all information, VECTORS and Materials comprised
         in the Licensed Know-How to be transferred to LICENSEE pursuant to this
         Agreement shall be so transferred in the case of written information,
         by memoranda bearing the mention "Confidential", and, in the case of
         Materials, by clearly marked and numbered containers. LICENSEE shall
         designate an individual who shall be responsible for receiving
         information and Materials from VRI and/or its Affiliates and the
         Parties agree that such information and Materials shall in all cases
         (except where the Parties agree otherwise) be sent solely to the
         attention of such individual. Upon receipt of information and/or
         Materials, the designated individual shall, on behalf of LICENSEE, send
         an acknowledgement to VRI and/or its Affiliates confirming receipt of
         information and/or Materials. The Parties agree that they shall in good
         faith work together to establish and maintain a system to record the
         transmission of information and/or Materials under this Agreement and
         make all commercially reasonable efforts to ensure such system is
         followed.

2.3.4.   CONFIDENTIALITY.





                                       9
<PAGE>   10


         All information transferred pursuant to this Agreement shall be deemed
         to be "Confidential Information" in accordance with Section 8.1.

2.3.5.   SUPPLY OF VECTOR.

         VRI hereby represents and warrants that any and all quantities of
         VECTOR which may be supplied hereunder by VRI or its Affiliates to
         LICENSEE for use in clinical trials in humans shall be manufactured in
         accordance with current Good Manufacturing Practices (cGMP) as in force
         in the country where such VECTOR shall be manufactured and shall meet
         VECTOR specifications as shall be agreed otherwise by the Parties. The
         sole and exclusive remedy for LICENSEE under this paragraph shall be
         for VRI to provide replacement VECTOR complying with agreed-upon
         specifications, free of any charge, in quantity equal to LICENSEE's
         original order, except where VRI liability is established to be gross
         negligence or willful misconduct (and LICENSEE did not use VECTOR with
         knowledge of the non-compliance hereunder), in which case VRI shall
         indemnify LICENSEE as provided herein.

ARTICLE 3 - DEVELOPMENT AND COMMERCIALIZATION.

3.1.     DEVELOPMENT AND COMMERCIALIZATION EFFORTS.

         LICENSEE (i) shall use commercially reasonable efforts to diligently
         conduct such preclinical and clinical trials that are necessary or
         desirable to obtain all regulatory approvals to develop and
         commercialize such PRODUCTS, (ii) shall diligently develop and obtain
         necessary approval to market such PRODUCTS (including, as the case may
         be, pricing approval), and (iii) shall commence marketing and market
         such PRODUCTS in each country in which LICENSEE has received all
         applicable regulatory approvals therefor. LICENSEE shall comply with
         all applicable good laboratory, clinical and manufacturing practices in
         the development and commercialization of such PRODUCTS, and shall cause
         its Affiliates and subcontractors to do the same. LICENSEE shall be
         solely responsible for funding all costs of the development and
         commercialization of each such PRODUCTS.

3.2.     SUB-CONTRACTS TO VRI.

         LICENSEE and VRI have agreed to have part of the research and
         development work with respect to PRODUCTS sub-contracted to VRI
         pursuant to and in accordance with the terms and conditions set forth
         in APPENDIX A.

         LICENSEE and VRI may agree to have VECTOR manufacturing sub-contracted
         to VRI, in which case such contract manufacturing shall be subject to
         terms and conditions set forth in APPENDIX B.

3.3.     DEVELOPMENT AND COMMERCIALIZATION REPORTS.

         During the term of this Agreement, LICENSEE shall keep VRI reasonably
         informed as to the progress of the development of PRODUCTS by notifying
         VRI of completion of each significant step.

         In addition, LICENSEE agrees to update the list of HPC Antigens which
         constitute the Schedule B to this Agreement, on a quarterly basis, by
         indicating in writing



                                       10
<PAGE>   11
                                                         CONFIDENTIAL TREATMENT



         which Other Hp Antigens, if any, are included in such list and which
         HPC Antigens, if any, are excluded therefrom and then become Other Hp
         Antigens.

         All information disclosed by LICENSEE pursuant to this Section 3.3
         shall be subject to Article 8 hereof.


ARTICLE 4 - ROYALTIES AND MILESTONES.

4.1.     EARNED ROYALTIES.

         During the Royalty Term, LICENSEE shall pay to VRI a royalty of [*].

4.2.     THIRD-PARTY ROYALTIES.

         If LICENSEE, its Affiliates or Sublicensees is required to pay
         royalties to any Third-Party in order to make, have made, use or sell a
         PRODUCT in a country or to make, have made or use VECTOR for use in
         such PRODUCT in such country, then the royalty set-forth in Section 4.1
         hereof for such PRODUCT in such country shall be reduced by [*].

4.3.     SINGLE ROYALTY: NON-ROYALTY SALES.

         In no event shall more than one royalty be payable under Section 4.1.
         hereof with respect to a particular unit of PRODUCTS. No royalty shall
         be payable under this Article 4 with respect to sales of PRODUCTS among
         LICENSEE and its Affiliates (provided that where a distributor is an
         Affiliate, but neither a Subsidiary of LICENSEE nor a Subsidiary of
         OraVax or PMC -other than HPC-, such distributor shall be deemed a
         Third-Party), or among Sublicensees and their Affiliates, or among
         LICENSEE and its Affiliates, but a royalty shall be due upon the
         subsequent sale of the PRODUCTS to a Third-Party. No royalty shall be
         payable for (i) PRODUCTS used by LICENSEE, its Affiliates or
         Sublicensees, for research including, without limitation, in clinical
         trials, or (ii) customary quantities of PRODUCTS distributed as free
         samples.

4.4.     MILESTONE PAYMENTS.

         As additional consideration for the LICENSE, rights and privileges
         granted to it hereunder, LICENSEE shall pay to VRI the following
         milestone payments within thirty (30) days of the occurrence of each
         event set forth below (unless otherwise specified below), whether such
         events are achieved by LICENSEE, its Affiliates or Sublicensees:

         (a)      [*];




/*/ Confidential material omitted and filed separately with the Securities and
    Exchange Commission.



                                       11
<PAGE>   12
                                                         CONFIDENTIAL TREATMENT


         (b)     [*];

         (d)     [*];

         (e)     [*];

         (f)     [*].

         The above-mentioned milestone payments shall be payable only once each.

ARTICLE 5 - ROYALTY REPORTS AND ACCOUNTING.

5.1.     REPORTS, EXCHANGE RATES.

         During the term of this Agreement following the First Commercial Sale,
         LICENSEE shall furnish to VRI, with respect to each Calendar Quarter, a
         written report showing in reasonably specific detail, on a
         country-by-country basis, (a) the gross sales of PRODUCTS sold by
         LICENSEE, its Subsidiaries and its Sublicensees in the Territory during
         the corresponding Calendar Quarter and the calculation of Net Sales
         from such gross sales; (b) the royalties payable in United States
         dollars, if any, which shall have accrued hereunder based upon Net
         Sales of PRODUCTS; (c) the withholding taxes, if any, required by law
         to be deducted in respect of such royalties; (d) the date of the First
         Commercial Sale of PRODUCTS having occurred in each country in the
         Territory during the corresponding Calendar Quarter; and (e) the
         exchange rates used in determining the royalty amount expressed in
         United States dollars.

         With respect to sales (if any) of PRODUCTS invoiced in United States
         dollars, the gross sales, Net Sales, and royalties payable shall be
         expressed in United Sates dollars. With respect to sales of PRODUCTS
         invoiced in a currency other than United Sates dollars, the gross
         sales, Net Sales and royalties payable shall be expressed in the
         currency of the invoice issued by the Party making the sale together
         with the United States dollars equivalent of the royalty payable,
         calculated using the rate of exchange published in the WALL STREET
         JOURNAL for such currency on the last business day of the concerned
         Calendar Quarter.

         Reports and payments shall be due on the forty fifth (45th) day
         following the close of each Calendar Quarter. LICENSEE shall keep
         complete and accurate records in sufficient detail to properly reflect
         all gross sales and Net Sales and to enable the royalties payable
         hereunder to be determined.





/*/ Confidential material omitted and filed separately with the Securities and
    Exchange Commission.


                                       12
<PAGE>   13


5.2.     AUDITS.

5.2.1.   Upon the written request of VRI and not more than once in each calendar
         year, LICENSEE shall permit an independent certified public accounting
         firm of internationally recognized standing, selected by VRI and
         reasonably acceptable to LICENSEE, at VRI's expense, to have access
         during normal business hours to such of the records of LICENSEE as may
         be reasonably necessary to verify the accuracy of the royalty reports
         hereunder for any year ending not more than three (3) years prior to
         the date of such request. The accounting firm shall disclose to VRI
         only whether the records are correct or not and the specific details
         concerning any discrepancies. No other information shall be shared.


5.2.2.   If such accounting firm concludes that additional royalties were owed
         during such period, LICENSEE shall pay the additional royalties within
         thirty (30) days of the date VRI delivers to LICENSEE such accounting
         firm's written report so concluding. The fees charged by such
         accounting firm shall be paid by VRI; PROVIDED, HOWEVER, if the audit
         discloses that the royalties payable by LICENSEE for the audited period
         are more than one hundred and two percent (102%) of the royalties
         actually paid for such period, then LICENSEE shall pay the reasonable
         fees and expenses charged by such accounting firm.


5.2.3.   LICENSEE shall include in each permitted sublicense granted by it
         pursuant to the Agreement a provision requiring the Sublicensee to make
         reports to LICENSEE, to keep and maintain records of sales made
         pursuant to such sublicense and to grant access to such records by
         VRI's independent accountant to the same extent required with respect
         to LICENSEE's records under this Agreement.

5.2.4.   Except in the case of circumstances which would have prevented an error
         or anomaly from being disclosed during the audit hereabove mentioned,
         such as fraud or other failure to provide accurate information, upon
         the expiration of three (3) years following the end of any calendar
         year, the calculation of royalties payable with respect to such year
         shall be binding and conclusive upon VRI, and LICENSEE, its Affiliates
         and Sublicensees shall be released from any liability or accountability
         with respect to royalties for such year.


5.3.     CONFIDENTIAL FINANCIAL INFORMATION.

         VRI shall treat all financial information subject to review under this
         Article 5 or under any sublicense as confidential, and shall cause its
         accounting firm to retain all such financial information in confidence.



ARTICLE 6 - PAYMENTS.

6.1.     PAYMENT TERMS.



                                       13
<PAGE>   14
                                                         CONFIDENTIAL TREATMENT


         Royalties shown to have accrued by each royalty report provided for
         under Article 5 of this Agreement shall be due on the date such royalty
         report is due. Payment of royalties in whole or in part may be made in
         advance of such due date.

6.2.     PAYMENT METHOD.

         Except as provided in this Section 6.2., all payments by LICENSEE to
         VRI under this Agreement shall be paid in United States dollars, and
         all such payments shall be made without deduction of bank transfer fees
         by bank wire transfer in immediately available funds to the following
         bank account:

------------------------------------------------------
        Bank         :  [*]


        Account No.  :  [*]
        Account name :  [*]
------------------------------------------------------

         or to any other bank account designated in writing from time to time by
         VRI to LICENSEE.

6.3.     EXCHANGE CONTROL.

         If at any time legal restrictions prevent the prompt remittance of part
         or all royalties with respect to any country in the Territory where
         PRODUCTS are sold, payment shall be made through such lawful means or
         method as the Parties reasonably shall determine or, at VRI's
         discretion, royalties shall be based on HPC sales (if any) to HPC's
         Subsidiary or Sublicensee in such country.

6.4.     WITHHOLDING TAXES.

         Royalties and milestone payments shall be paid by LICENSEE to VRI,
         after deduction of any applicable withholding taxes. Prior to any
         payment by LICENSEE to VRI, LICENSEE shall provide to VRI any forms
         required to attest VRI's fiscal domiciliation in order to allow
         LICENSEE to claim application of the reduced rate of withholding tax
         provided for in any applicable bilateral fiscal convention. VRI shall
         promptly return such forms to LICENSEE. In the event VRI fails to
         promptly return such forms duly filled and signed, LICENSEE shall
         declare and pay withholding tax at the common law rate of the
         applicable corporate income tax, and such tax shall then be deducted
         from the corresponding payment by LICENSEE to VRI. LICENSEE shall pay
         withholding tax to the proper taxing authority and proof of payment of
         such tax shall be secured and sent to VRI as evidence of such payment.

ARTICLE 7 - INFRINGEMENT ACTIONS BY THIRD-PARTIES.

If LICENSEE, VRI or their respective Affiliates, or LICENSEE's Sublicensees, is
sued by a Third-Party for infringement of a Third-Party's patent because of the
manufacture, use or sale of PRODUCTS or manufacture or use of VECTOR, the Party
which has been sued shall promptly notify the other Party in writing of the
institution of such suit, in which event the other Party shall have the right to
be represented by advisory counsel of its own selection, at its own expense, and
shall cooperate fully in the defense of such suit and furnish to the Party(ies)
that is(are) sued all evidences and assistance in its control.




/*/ Confidential material omitted and filed separately with the Securities and
    Exchange Commission.


                                       14
<PAGE>   15


The Party controlling the suit may not settle the suit or otherwise consent to
an adverse judgment in such suit that diminishes the rights or interests of the
non-controlling Party without the express written consent of the non-controlling
Party. Any judgments, awards, settlements or damages payable with respect to
legal proceedings covered by this Article 7 shall be paid by the Party against
whom the award has been made.

ARTICLE 8 - CONFIDENTIALITY.

8.1.     NON-DISCLOSURE AND RESTRICTION-OF-USE OBLIGATIONS.

         Except as otherwise provided in this Article 8, during the term of this
         Agreement and for a period of ten (10) years after termination of this
         Agreement under Sections 10.3. or 10.4., each Party shall maintain in
         confidence, and use only for purposes as expressly authorized and
         contemplated by this Agreement, all information and data supplied by
         the other Party under this Agreement, including but not limited to
         LICENSED KNOW-HOW, Manufacturing Know-How and VECTOR Improvements. For
         purposes of this Article 8, information and data described above shall
         be hereinafter referred to as "CONFIDENTIAL INFORMATION".

8.2.     PERMITTED DISCLOSURES.

         To the extent it is reasonably necessary or appropriate to fulfill its
         obligations or exercise its rights under this Agreement, (i) a Party
         may disclose Confidential Information it is otherwise obligated under
         this Article 8 not to disclose, to its Affiliates, Sublicensees,
         consultants, outside contractors and clinical investigators, on a
         need-to-know basis, provided that such Persons agree to keep the
         Confidential Information confidential and not use the Information for
         the same time period and to the same extent as such Party is required;
         and (ii) a Party may disclose such Confidential Information to
         governmental or other regulatory authorities to the extent that such
         disclosure is required by applicable law, regulation or court order, or
         is reasonably necessary to obtain patents, copyrights or authorizations
         to conduct clinical trials with, or to commercially market PRODUCTS,
         provided that the disclosing Party shall provide written notice to the
         other Party and sufficient opportunity to object to such disclosure or
         to request confidential treatment thereof.

         The obligation not to disclose or use Confidential Information shall
         not apply to any part of such Information (including LICENSED KNOW-HOW,
         Manufacturing Know-How and VECTOR Improvements) that (i) is or becomes
         patented, published or otherwise part of the public domain or publicly
         available other than by acts of the Party obligated not to disclose
         such Information, or of its Affiliates or Sublicensees, in
         contravention of this Agreement; (ii) is disclosed to the receiving
         Party or its Affiliates or Sublicensees by a Third Party, provided such
         Information was not obtained by such Third-Party directly or indirectly
         from the other Party, its Affiliates or Sublicensees, under or pursuant
         to this Agrement on a confidential basis and otherwise had a lawful
         right to disclose the information; (iii) prior to disclosure under




                                       15
<PAGE>   16


         the Agreement, was already in the possession of the receiving Party or
         its Affiliates or Sublicensees, provided such Information was not
         obtained directly or indirectly from the other Party under this
         Agreement; (iv) is independently developed by the receiving Party
         without reliance on the Confidential Information disclosed by the other
         Party hereunder, (v) is disclosed in a press release agreed to by both
         Parties hereto in accordance with Section 8.4. hereinafter or (vi) both
         Parties have agreed to publish.

8.3.     TERMS OF THE AGREEMENT.

         LICENSEE and VRI shall not disclose any terms or conditions of this
         Agreement to any Third-Party without the prior consent of the other
         Party, except (a) to Persons with whom LICENSEE or VRI has entered into
         or proposes to enter into a business relationship to which this
         Agreement is relevant and substantial, provided that such Persons shall
         enter into the required confidentiality agreement, or (b) as required
         by applicable laws, regulations or a court order, provided that the
         disclosing Party shall provide written notice to the other Party and
         sufficient opportunity to object to such disclosure or to request
         confidential treatment thereof.

8.4.     PRESS RELEASES AND OTHER DISCLOSURES TO THIRD-PARTIES

         Neither VRI nor HPC shall, without the prior written consent of the
         other, issue any press release or make any other public announcement or
         furnish any statement to any Person (other than either Parties'
         respective Affiliates) concerning the existence of this Agreement and
         the transactions contemplated by this Agreement, except for (i) general
         statement referring to the existence of this Agreement, specifying the
         Field of Use and identity of the Parties but no other details, (ii)
         disclosures made in compliance with sections 8.2. and 8.3. hereof,
         (iii) attorneys, consultants, and accountants retained to represent
         them in connection with the transactions contemplated hereby or as may
         be reasonably necessary to either Party's bankers, investors, attorneys
         or other professional advisors in connection with a merger or
         acquisition, provided such advisors are bound by confidentiality
         obligations essentially identical to those provided for herein, and
         (iv) occasional, brief comments by the respective officers of HPC,
         OraVax, PMC and VRI consistent with such guidelines for public
         statements as may be mutually agreed by HPC and VRI made in connection
         with routine interviews with analysts or members of the financial
         press. In addition, either Party (after consultation with counsel) in
         its own right may make such further announcements and disclosures, if
         any, as may be required by applicable laws and regulations, in which
         case the Party making the announcement or disclosure shall use its best
         efforts to give advance notice to, and discuss such announcement or
         disclosure with, the other Party.

8.5.     Notwihstanding anything else to the contrary, LICENSEE agrees that VRI
         Technology shall be used only for the research, development,
         manufacture, use and sale of PRODUCTS and that in the event that the
         LICENSE is terminated, LICENSEE agrees not to use VRI Technology and
         LICENSEE VECTOR Improvements for the research, development,
         manufacture, use or sale of any product or process including but not
         limited to PRODUCTS.



                                       16
<PAGE>   17


ARTICLE 9 - INVENTIONS AND PATENTS.

9.1.     OWNERSHIP OF INVENTIONS.

         The entire right and title to technology, whether or not patentable,
         and any patent applications or patents based thereon, made or conceived
         during the term of this Agreement (other than Research Inventions as
         defined in APPENDIX A attached hereto, if any), (a) by employees or
         others acting solely on behalf of VRI or its Affiliates, shall be owned
         solely by VRI, (b) by employees or others acting solely on behalf of
         LICENSEE or its Affiliates, shall be owned solely by LICENSEE, and (c)
         by both employees or others acting on behalf of LICENSEE or its
         Affiliates and on behalf of VRI or its Affiliates shall be jointly
         owned by LICENSEE and VRI (the "JOINT INVENTIONS"). Each Party promptly
         shall disclose to the other Party the making, conception or reduction
         to practice of VECTOR Improvements by employees or others acting on
         behalf of such Party. VRI and LICENSEE each hereby represents that all
         employees and other Persons acting on its behalf in performing its
         obligations under this Agreement shall be obligated under a binding
         written agreement to assign to it, or as it shall direct, all VECTOR
         Improvements conceived or reduced to practice by such employees or
         other Persons. The provisions of this Section 9.1 are subject to
         Section 2.2 hereof.

9.2.     PATENT PROSECUTION AND MAINTENANCE.

         VRI shall be responsible for and shall control the preparation, filing,
         prosecution, grant and maintenance of all LICENSED PATENTS. VRI shall
         prepare, file, prosecute and maintain such LICENSED PATENTS in good
         faith consistent with its customary patent policy and its reasonable
         business judgement, and shall consider in good faith the interests of
         LICENSEE in so doing. LICENSEE shall re-imburse VRI a share of
         reasonable costs of prosecution and maintenance of all LICENSED PATENTS
         as far as such costs are borne by VRI in the normal course of business
         after the Effective Date and for so long as the LICENSE to the relevant
         LICENSED PATENTS continues in effect. Such share shall be an amount
         equal to the total of the costs mentioned hereinabove multiplied by a
         fraction having as a numerator one (1), and as a denominator the total
         number of licences granted by VRI to Third-Parties with respect to
         LICENSED PATENTS. VRI shall furnish to HPC an estimated yearly budget
         for such costs.

9.3.     ENFORCEMENT OF LICENSED PATENTS.

         In the event that LICENSED PATENTS are infringed by any Third-Party in
         the Field of Use, LICENSEE shall have the right, but not the
         obligation, to institute and prosecute any action or proceeding under
         LICENSED PATENTS with respect to such infringement, by counsel of its
         choice, including any declaratory judgement action arising from such
         infringement. Any amounts recovered from Third-Parties with respect to
         the LICENSED PATENTS in such action shall be retained by LICENSEE.
         LICENSEE shall not have the right to settle, compromise or take any
         action in such litigation which diminishes, limits or inhibits the
         scope, validity or enforceability of LICENSED PATENTS without the
         express permission of VRI. LICENSEE shall keep VRI advised of the
         progress of such proceedings.





                                       17
<PAGE>   18


         In the event that a Third-Party is infringing any LICENSED PATENTS in
         the Field of Use and LICENSEE does not elect to institute an action,
         VRI shall have the right, but not the obligation, to commence an
         infringement suit under the LICENSED PATENTS against such infringer and
         shall retain any recovery; provided that it so notifies LICENSEE.

ARTICLE 10 - TERM AND TERMINATION.

10.1.    EXPIRATION.

         Unless terminated earlier pursuant to this Article 10 or Article 12,
         the Agreement shall expire on the expiration of LICENSEE's obligations
         to pay royalties under the Agreement in accordance with the Royalty
         Term. Thereafter, LICENSEE and Sublicensees shall have a perpetual,
         fully paid-up, royalty-free, non-cancellable, worldwide license or
         sub-license (whichever is applicable) to the VRI Technology.

10.2.    After First Commercial Sale of a PRODUCT or PRODUCTS in a country,
         royalties for any other PRODUCT or PRODUCTS introduced into such
         country will only be payable if a Valid Patent Claim is in effect in
         the United States or Europe at the time such PRODUCT or PRODUCTS are
         first offered for sale in such country, provided that if LICENSEE has
         ceased to sell a PRODUCT in a country prior to the payment of royalties
         in such country for ten (10) years, any additional PRODUCT or PRODUCTS
         sold in such country thereafter will be subject to royalties without
         regard to the existence of a Valid Patent Claim until VRI has received
         at least ten (10) years of Royalty payments in such country.

10.3.    TERMINATION BY LICENSEE.

         LICENSEE shall have the right at any time as from January 1, 1998, in
         its sole discretion, to terminate this Agreement, by giving not less
         than three (3) months' prior written notice to VRI of such termination.

10.4.    TERMINATION FOR CAUSE.

         (i)      Either Party may terminate this Agreement, at its option, upon
                  or after the breach of any material provision of the
                  Agreement, if the breaching Party has not cured such breach
                  within ninety (90) days after written notice thereof from the
                  other Party.

         (ii)     LICENSEE or VRI may terminate this Agreement upon written
                  notice to the other party if the other party makes a general
                  assignment for the benefit of creditors, is the subject of
                  proceedings in voluntary or involuntary bankruptcy or has a
                  receiver or trustee appointed for substantially all of its
                  property; PROVIDED that in the case of an involuntary
                  bankruptcy proceeding such right to terminate shall only
                  become effective if the other party consents thereto or such
                  proceeding is not dismissed within ninety (90) days after the
                  filing thereof.






                                       18



<PAGE>   19

                  Each of the parties hereto acknowledges and agrees that this
                  Agreement (i) constitutes a license of Intellectual Property
                  (as such term is defined in the United States Bankruptcy code,
                  as amended (the "Code"), and (ii) is an executory contract,
                  with significant obligations to be performed by each party
                  hereto. The parties agree that LICENSEE may fully exercise all
                  of its rights and elections under the Code, including, without
                  limitation, those set forth in Section 365(n) of the Code. The
                  parties further agree that, in the event that LICENSEE elects
                  to retain its rights as a licensee under the Code, LICENSEE
                  shall be entitled to complete access to any technology
                  licensed to it hereunder and all embodiments of such
                  technology. Such embodiments of the technology shall be
                  delivered to LICENSEE not later than (a) the commencement of
                  bankruptcy proceedings against VRI, unless VRI elects to
                  perform its obligations under this Agreement, or (b) if not
                  delivered under (a) above, upon the rejection of this
                  Agreement by or on behalf of VRI.

10.5.    EFFECT OF EXPIRATION AND TERMINATION.

         Expiration or termination of the Agreement shall not relieve the
         Parties of any obligation accruing prior to such expiration or
         termination. The provisions of Sections 2.1.3.(v) and 9.1. and Articles
         8 and 11 shall survive the expiration or termination of the Agreement.

ARTICLE 11 - INDEMNITY.

11.1.    DIRECT INDEMNITY.

11.1.1.  Each Party shall indemnify and hold harmless the other Party, its
         Affiliates, and their respective directors, officers, shareholders,
         agents, consultants and employees from and against all Third-Party
         claims, demands, liabilities, damages and expenses, including
         attorneys' fees and costs (collectively, the "LIABILITIES") arising out
         of the breach of any material provision of this Agreement by, or an act
         or an omission of, the indemnifying Party, except to the extent such
         Liabilities resulted from the gross negligence, recklessness or
         intentional acts or omissions of the other Party.

11.1.2.  LICENSEE shall defend, indemnify and hold harmless VRI, its Affiliates,
         licensors, their respective directors, officers, shareholders, agents,
         consultants and employees, from and against all Liabilities suffered or
         incurred arising out of any Third-Party claims in connection with the
         manufacture, design, testing, possession, distribution, use, sale or
         other disposition by or through LICENSEE, its Affiliates or
         Sublicensees of any PRODUCTS or VECTOR, except in each case to the
         extent such Liabilities resulted from the gross negligence,
         recklessness or intentional acts or omissions of VRI, and except where
         VRI's liability is established in accordance with EXHIBIT 1 to APPENDIX
         B attached hereto as far as supply of VECTOR is concerned.



                                       19
<PAGE>   20

11.2.    PROCEDURE.

         A Party (the "INDEMNITEE") that intends to claim indemnification under
         this Article 11 shall promptly notify the other Party (the
         "INDEMNITOR") of any Liability or action in respect of which the
         Indemnitee intends to claim such indemnification, and the Indemnitor
         shall have the right to participate in, and, to the extent the
         Indemnitor so desires, jointly with any other Indemnitor similarly
         noticed, to assume the defense thereof with counsel selected by the
         Indemnitor; PROVIDED, HOWEVER, that the Indemnitee shall have the
         right to retain its own counsel, with the fees and expenses to be paid
         by the Indemnitor, if representation of such Indemnitee by the counsel
         retained by the Indemnitor would be inappropriate due to actual or
         potential differing interests between such Indemnitee and any other
         Party represented by such counsel in such proceedings.

         The indemnity obligations under this Article 11 shall not apply to
         amounts paid in settlement of any loss, claim, damage, liability or
         action if such settlement is effected without the consent of the
         Indemnitor, which consent shall not be withheld unreasonably. The
         failure to deliver notice to the Indemnitor within a reasonable time
         after the commencement of any such action, if prejudicial to its
         ability to defend such action, shall relieve such Indemnitor of any
         liability to the Indemnitee under this Article 11. The Indemnitee, its
         Affiliates, employees and agents, shall cooperate fully with the
         Indemnitor and its legal representatives in the investigation of any
         action, claim or liability covered by this indemnification.

ARTICLE 12 - FORCE MAJEURE.

No Party (or any of its Affiliates) shall be held liable or responsible to the
other Party (or any of its Affiliates) nor be deemed to have defaulted under or
breached the Agreement for failure or delay in fulfilling or performing any term
of the Agreement when such failure or delay is caused by or results from causes
beyond the reasonable control of the affected Party (or any of its Affiliates)
including but not limited to fire, floods, embargoes, war, acts of war (whether
war be declared or not), insurrections, riots, civil commotions, strikes,
lockouts or other labor disturbances, acts of God or acts, omissions or delays
in acting by any governmental authority or the other Party (collectively,
"EVENTS OF FORCE MAJEURE"); PROVIDED, HOWEVER, that the affected Party (i)
shall immediately notify the other Party of the occurrence of any such Event of
Force Majeure and (ii) shall exert all reasonable efforts to eliminate, cure or
overcome any such Event of Force Majeure and to resume performance of its
covenants with all possible speed; and PROVIDED, FURTHER, that nothing
contained herein shall require any Party to settle on terms unsatisfactory to
such Party any strike, lockout or other labor difficulty, any investigation or
proceeding by any governmental authority or any litigation by any Third-Party.
Notwithstanding the foregoing, to the extent that an Event of Force Majeure
continues for a period in excess of six (6) months, the affected Party shall
promptly notify in writing the other Party of such Event of Force Majeure and
within four (4) months of the other Party's receipt of such notice, the Parties
agree to negotiate in good faith either (i) to resolve the Event of Force
Majeure, if possible, (ii) to extend by mutual agreement the time period to
resolve, eliminate, cure or overcome such Event of Force Majeure, (iii) to amend
this Agreement to the extent reasonably possible, or (iv) to terminate this
Agreement.

ARTICLE 13 - ASSIGNMENT.




                                       20
<PAGE>   21


This Agreement may not be assigned or otherwise transferred, nor, except as
expressly provided hereunder, may any right or obligations hereunder be assigned
or transferred to any Third-Party by either Party without the consent of the
other Party; PROVIDED, HOWEVER, that either Party may, without such consent,
assign this Agreement and its rights and obligations hereunder to any of its
Affiliates or in connection with the transfer or sale of all or substantially
all of its business, or in the event of its merger or consolidation or change in
control or similar transaction. Any permitted assignee shall assume all
obligations of its assignor under this Agreement.

Without limiting the generality of the foregoing, without the prior written
consent of LICENSEE, VRI shall not under any circumstances assign or transfer
any VRI Technology in the Field of Use unless the assignee expressly agrees in
writing that the LICENSE shall remain in full force and effect pursuant to its
terms and such assignment shall not relieve the assignor of any of its
obligations under this Agreement. Each Party acknowledges that the other Party
would suffer irreparable injury in the event of any breach of this Article 13
and that therefore the remedy at law for any breach or threatened breach hereof
by any Party shall be inadequate. Accordingly, upon a breach or threatened
breach hereof by any Party, the other Party shall, in addition and without
prejudice to any other rights and remedies it may have, be entitled as a matter
of right, without proof of actual damages, to seek specific performance hereof
and to such other injunctive or equitable relief to enforce or prevent any
violations (whether anticipatory, continuing or future) hereof.

ARTICLE 14 - NOTIFICATION OF PATENT TERM RESTORATION - PATENT EXTENSIONS.

VRI shall notify LICENSEE of (a) the issuance of each U.S. patent included
within the LICENSED PATENTS, giving the date of issue and patent number for each
such patent, and (b) each notice pertaining to any patent included within the
LICENSED PATENTS which it receives as patent owner pursuant to the United States
Drug Price Competition and Patent Term Restoration Act of 1984 (hereinafter
called the "Act"), including notices pursuant to sections 101 and 103 of the
Act from Persons who have filed an abbreviated new drug application ("ANDA").
Such notices shall be given promptly, but in any event within five (5) calendar
days of each such patent's date of issue or receipt of each such notice
pursuant to the Act, whichever is applicable. VRI shall notify LICENSEE of each
filing for patent term restoration under the Act, any allegations of failure to
show due diligence and all awards of patent term restoration (extensions) with
respect to the LICENSED PATENTS.

Likewise, VRI or LICENSEE, as the case may be, shall inform the other Party of
patent extensions and periods of data exclusivity in the rest of the world
regarding any PRODUCTS and more generally the Parties shall diligently cooperate
with respect to any procedures for patent and period of data exclusivity
extensions, such as but not limited to Supplementary Protection Certificates,
the above-mentioned Patent Term Restoration and corresponding GATT regulations.

ARTICLE 15 - ADVERSE EXPERIENCE REPORTING.

During the term of the Agreement, each Party shall notify the other immediately
of any information (howsoever obtained and from whatever source) concerning any
unexpected side effect, injury, toxicity or sensitivity reaction, or any
unexpected incidence, and the severity thereof, associated with the clinical
uses, studies, investigations, tests and marketing of PRODUCTS and, to the
extent feasible, any other product containing VECTOR (hereinafter, a "PRODUCT"),
or VECTOR. For purposes of this Article 15, "UNEXPECTED" shall mean (x) for a
non-marketed Product, an experience that is not identified in nature, severity
or frequency in




                                       21
<PAGE>   22

the current clinical investigator's confidential information brochure, and (y)
for a marketed Product, an experience which is not listed in the current
labeling for such Product, and includes an event that may be symptomatically and
pathophysiologically related to an event listed in the labelling but differs
from the event because of increased frequency or greater severity or
specificity.

Each Party further shall immediately notify the other of any information
received regarding any threatened or pending action by an agency which may
affect the safety and efficacy claims of a Product. Upon receipt of any such
information, the Parties shall consult with each other in an effort to arrive at
a mutually acceptable procedure for taking appropriate action; provided,
however, that nothing contained herein shall be construed as restricting either
Party's right to make a timely report of such matter to any government agency or
take other action that it deems to be appropriate or required by applicable law
or regulation.

ARTICLE 16 - SEVERABILITY.

Each Party hereby agrees that it does not intend to violate any public policy,
statutory or common laws, rules, regulations, treaty or decision of any
government agency or executive body thereof of any country or community or
association of countries. Should one or more provisions of this Agreement be or
become invalid, the Parties hereto shall substitute, by mutual consent, valid
provisions for such invalid provisions which valid provisions in their economic
effect are sufficiently similar to the invalid provisions that it can be
reasonably assumed that the Parties would have entered into this Agreement with
such provisions. In case such provisions cannot be agreed upon, the invalidity
of one or several provisions of this Agreement shall not affect the validity of
this Agreement as a whole, unless the invalid provisions are of such essential
importance to this Agreement that it is to be reasonably assumed that the
Parties would not have entered into this Agreement without the invalid
provisions.

ARTICLE 17 - MISCELLANEOUS.

17.1.    NOTICES.

         Any consent, notice or report required or permitted to be given or made
         under this Agreement by one of the Parties hereto to the other shall be
         in writing, delivered personally or by facsimile and promptly confirmed
         by personal delivery, first class air mail or courier, postage prepaid
         (where applicable), addressed to such other Party at its address
         indicated below, or to such other address as the addressee shall have
         last furnished in writing to the addressor and (except as otherwise
         provided in this Agreement) shall be effective upon receipt by the
         addressee.

         ~ IF TO VRI:

           VIRUS RESEARCH INSTITUTE, INC.
           61 Moulton Street
           Cambridge MA 02138 USA
           Attention: President



                                       22
<PAGE>   23


           Telefax: (617) 864-6334
           Telephone: (617) 864-6232

         ~ IF TO LICENSEE:

           MERIEUX ORAVAX S.N.C.
           c/o PASTEUR MERIEUX Serums & Vaccins S.A.
           58, avenue Leclerc
           69007 Lyon, France
           Attention: Senior Vice-President, Legal & Corporate Affairs and
           General Counsel, Legal Department
           Telefax: 33.4.72.73.70.61
           Telephone: 33.4.72.73.77.84


           ORAVAX MERIEUX CO.
           c/o ORAVAX, INC.
           38, Sidney Street
           Cambridge, MA 02139, USA;
           Attention: President & Chief Executive Officer
           Telefax: (617) 494-1741
           Telephone: (617) 494-1339

17.2.    APPLICABLE LAW.

         The Agreement shall be governed by and construed in accordance with the
         laws of the State of Massachusetts, without regard to the conflict of
         law principles thereof.

17.3.    REPRESENTATIONS, WARRANTIES AND COVENANTS.

17.3.1.  REPRESENTATIONS AND WARRANTIES OF MERIEUX ORAVAX S.N.C.

         (a)      Merieux OraVax S.N.C. is a Societe en Nom Collectif duly
                  organized and existing under the laws of France, with the
                  corporate power to own, lease and operate its properties and
                  to carry on its business as now conducted.

         (b)      Merieux OraVax S.N.C. has all necessary corporate power and
                  authority to enter into this Agreement and to consummate the
                  transactions contemplated hereby.

         (c)      The execution, delivery and performance of this Agreement by
                  Merieux OraVax S.N.C. does not conflict with or contravene the
                  statuts of Merieux OraVax S.N.C., nor will the execution,
                  delivery or performance of this Agreement conflict with or
                  result in a breach of, or entitle any party thereto to
                  terminate, any material agreement or instrument to which
                  Merieux OraVax S.N.C. is a party, or by which any of its
                  assets or properties are bound.

         (d)      This Agreement has been duly authorized, executed and
                  delivered by Merieux OraVax S.N.C. and constitutes a legal,
                  valid and binding agreement of Merieux OraVax S.N.C.,
                  enforceable against Merieux OraVax S.N.C. in accordance with
                  its terms, except as enforceability may be limited by
                  bankruptcy,





                                       23
<PAGE>   24


                  insolvency, moratorium, reorganization or other similar laws
                  affecting creditors' rights generally.

17.3.2.  REPRESENTATIONS AND WARRANTIES OF ORAVAX MERIEUX CO.

         (a)      OraVax Merieux Co. is a General Partnership duly organized and
                  existing under the laws of the State of Massachusetts, with
                  the corporate power to own, lease and operate its properties
                  and to carry on its business as now conducted.

         (b)      OraVax Merieux Co. has all necessary corporate power and
                  authority to enter into this Agreement and to consummate the
                  transactions contemplated hereby.

         (c)      The execution, delivery and performance of this Agreement by
                  OraVax Merieux Co. does not conflict with or contravene the
                  by-laws of OraVax Merieux Co., nor will the execution,
                  delivery or performance of this Agreement conflict with or
                  result in a breach of, or entitle any party thereto to
                  terminate, any material agreement or instrument to which
                  OraVax Merieux Co. is a party, or by which any of its assets
                  or properties are bound.

         (d)      This Agreement has been duly authorized, executed and
                  delivered by OraVax Merieux Co. and constitutes a legal, valid
                  and binding agreement of OraVax Merieux Co., enforceable
                  against OraVax Merieux Co. in accordance with its terms,
                  except as enforceability may be limited by bankruptcy,
                  insolvency, moratorium, reorganization or other similar laws
                  affecting creditors' rights generally.

17.3.3.  REPRESENTATIONS, WARRANTIES AND COVENANTS OF VRI.

         (a)      VRI is a corporation duly incorporated and validly existing as
                  a corporation in good standing under the laws of the State of
                  Delaware, with the corporate power to own, lease and operate
                  its properties and to carry on its business as now conducted.

         (b)      VRI has all necessary corporate power and authority to enter
                  into this Agreement and to consummate the transactions
                  contemplated hereby.

         (c)      The execution, delivery and performance of this Agreement by
                  VRI does not conflict with or contravene its certificate of
                  incorporation or by-laws, nor will the execution, delivery or
                  performance of this Agreement conflict with or result in a
                  breach of, or entitle any party thereto to terminate, any
                  material agreement or instrument to which VRI is a party, or
                  by which any of its assets or properties are bound.

         (d)      This Agreement has been duly authorized, executed and
                  delivered by VRI and constitutes a legal, valid and binding
                  agreement of VRI, enforceable against VRI in accordance with
                  its terms, except as enforceability may be limited by
                  bankruptcy, insolvency, moratorium, reorganization or other
                  similar laws affecting creditors' rights generally.

         (e)      All LICENSED PATENTS listed on SCHEDULE A have been registered
                  in, filed in or issued by the appropriate patent offices of
                  each jurisdiction as indicated on such SCHEDULE A, and in each
                  case is currently in effect and all maintenance




                                       24
<PAGE>   25

                  fees and renewals thereof have been duly made with respect
                  thereto. VRI owns or has full and exclusive rights to use and
                  exploit under licenses (and to license or sublicense) all its
                  rights under such LICENSED PATENTS and the LICENSED KNOW-HOW.
                  There have been no material claims made against VRI asserting
                  the invalidity or unenforceability of, or with respect to such
                  LICENSED PATENTS , the misuse of such LICENSED PATENTS or the
                  LICENSED KNOW-HOW, nor is VRI aware that any such claims
                  exist. VRI has not received a notice of conflict of such
                  LICENSED PATENTS or the LICENSED KNOW-HOW with the asserted
                  rights of others, or otherwise challenging its rights to use
                  any of such LICENSED PATENTS, or the LICENSED KNOW-HOW. EXCEPT
                  AS OTHERWISE EXPRESSLY SET FORTH IN THIS SECTION, NEITHER
                  PARTY MAKES ANY REPRESENTATION OR EXTENDS ANY WARRANTIES OF
                  ANY KIND EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
                  TO WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
                  PURPOSE, NON-INFRINGEMENT, OR VALIDITY OF ANY PATENT RIGHTS
                  ISSUED OR PENDING.

17.4.    DISPUTE RESOLUTION.

         The Parties agree that if any dispute or disagreement arises between
         LICENSEE on the one hand and VRI on the other in respect of this
         Agreement, they shall follow the following procedure in an attempt to
         resolve the dispute or disagreement.

         (a)      The Party claiming that such a dispute exists shall give
                  notice in writing ("NOTICE OF DISPUTE") to the other Party of
                  the nature of the dispute;

         (b)      Within twenty eight (28) business days of receipt of a Notice
                  of Dispute, a nominee or nominees of LICENSEE and a nominee or
                  nominees of VRI shall meet in person and exchange written
                  summaries reflecting, in reasonable detail, the nature and
                  extent of the dispute, and at this meeting they shall use
                  their reasonable endeavours to resolve the dispute;

         (c)      If, within a further period of twenty eight (28) business
                  days, the dispute has not been resolved or if, for any reason,
                  the required meeting has not been held, then the Parties agree
                  that any dispute shall be referred to an arbitrator appointed
                  by agreement of VRI and LICENSEE or, if no such agreement is
                  reached within sixty (60) business days after a Party
                  commences the arbitration, then by a panel of three
                  arbitrators, with each of LICENSEE and VRI to select one
                  arbitrator and those two arbitrators to select the third. If
                  all three arbitrators have not been selected within sixty (60)
                  business days after a Party commences the arbitration, then
                  the Parties agree to abide by the selection of the remaining
                  arbitrator to be named by a representative of the
                  International Chamber of Commerce.

                  The Parties agree that the Rules of the International Chamber
                  of Commerce shall govern such arbitration and that any
                  decision of the arbitrators shall be final and binding and
                  shall be enforceable in any court of competent jurisdiction
                  worldwide (regardless of whether one of the Parties fails or
                  refuses to participate in the arbitration) and shall be
                  enforced pursuant to the New-York Convention on the
                  Recognition and Enforcement of Arbitral Awards. The Parties
                  agree that all arbitrations shall be conducted in the English
                  language and that the exclusive venue of all arbitrations
                  shall be in London, England. The Party determined by the
                  arbitrators to be the Party




                                       25
<PAGE>   26

                  substantially prevailing in the arbitration shall be entitled
                  to recover its legal and consultants' fees and other costs
                  reasonably incurred in connection with the arbitration (as
                  determined by the arbitrators); and

         (d)      in the event of a dispute regarding any payments owing under
                  this Agreement, all undisputed amounts shall be paid promptly
                  when due and the balance, if any, promptly after resolution of
                  the dispute.

17.5.    ENTIRE AGREEMENT.

         This Agreement contains the entire understanding of the Parties with
         respect to the subject matter hereof. All express or implied agreements
         and understandings, either oral or written, heretofore made [-] are
         expressly superseded by this Agreement. This Agreement may be amended,
         or any term hereof modified, only by a written instrument duly executed
         by both Parties hereto.

17.6.    INDEPENDENT CONTRACTORS.

         VRI and LICENSEE each acknowledge that they shall be independent
         contractors and that the relationship between the two Parties shall not
         constitute a partnership, joint venture or agency. Neither VRI nor
         LICENSEE shall have the authority to make any statements,
         representations or commitments of any kind, or to take any action,
         which shall be binding on the other Party, without the prior consent of
         the other Party to do so.

17.7.    AFFILIATES.

         Each Party shall cause its respective Affiliates to comply fully with
         the provisions of this Agreement to the extent such provisions
         specifically relate to, or are intended to specifically relate to, such
         Affiliates, as though such Affiliates were expressly named as joint
         obligors hereunder.

17.8.    WAIVER.

         The waiver by either Party hereto of any right hereunder or the failure
         to perform or of a breach by the other Party shall not be deemed a
         waiver of any other right hereunder or of any other breach or failure
         by said other Party whether of a similar nature or otherwise.

17.9.    NO IMPLIED LICENCE.

         Nothing in this Agreement shall be deemed to constitute, by implication
         or otherwise, the grant by LICENSEE to VRI, or by VRI to LICENSEE, of
         any license to, or interest in, or other rights under any patent,
         patent application, proprietary





                                       26
<PAGE>   27


         know-how, trade secrets or other intellectual property rights owned or
         possessed by LICENSEE or VRI, whichever is applicable, except as
         expressly provided for herein.

17.10.   COUNTERPARTS.

         This Agreement may be executed in two or more counterparts, each of
         which shall be deemed an original, but all of which together shall
         constitute one and the same instrument.

IN WITNESS WHEREOF, the Parties have executed this Agreement as of the date
first set forth above.


For VIRUS RESEARCH INSTITUTE, INC.



By: /S/ J. Barrie Ward
   -------------------------
Name:  J. Barrie WARD
Title: Chairman & Chief Executive Officer.


For MERIEUX ORAVAX S.N.C.



By: /s/ Jean-Jacques Bertrand
    ---------------------------------------

Name: PASTEUR MERIEUX Serums & Vaccins S.A.
      Associe Gerant, represented by Jean-Jacques BERTRAND,
      Chairman, President & Chief Executive Officer



By: /s/ Lance K. Gordon
   ---------------------------------------
Name: ORAVAX JVM, Inc., Associe, represented by
      Lance K. GORDON, President and Chief Executive Officer





                                       27



<PAGE>   28
For ORAVAX MERIEUX, CO.


By:     /s/ Herve Tainturier
       ---------------------------------------
Name:  MERIEUX AMERICA HOLDINGS, Inc.
       General Partner, represented by Herve TAINTURIER, President



By:     /s/ Lance K. Gordon
       ---------------------------------------
Name:  ORAVAX JVM, Inc., general partner,
       represented by Lance K. GORDON, President



OraVax and PMC each hereby guarantee that their respective Affiliates, including
but not limited to Merieux OraVax S.N.C. and OraVax Merieux Co., shall perform
all obligations which are expressly imposed upon them pursuant to and in
accordance with this Agreement, and that OraVax and PMC shall each be bound by
the terms and conditions of this Agreement imposed on LICENSEE as if OraVax and
PMC were parties to this Agreement.



For ORAVAX INCORPORATED


By:    /s/ Lance K. Gordon
      ---------------------------------------
Name:  Lance K. GORDON
Title: President & Chief Executive Officer


For PASTEUR MERIEUX SERUMS & VACCINS S.A.


By:      /s/ Jean-Jacques Bertrand
        ------------------------------------
Name:  Jean-Jacques BERTRAND
Title: Chairman, President & Chief Executive Officer.




                                       28
<PAGE>   29
                                                         CONFIDENTIAL TREATMENT



                      -----------------------------------
                                   SCHEDULE A

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

                                LICENSED PATENTS
                      -----------------------------------



[*]






/*/ Confidential material omitted and filed separately with the Securities and
    Exchange Commission.




                                       29

<PAGE>   30
                                                         CONFIDENTIAL TREATMENT



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

                                   SCHEDULE B

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

                              LIST OF HPC ANTIGENS
                ------------------------------------------------




                [*]










/*/ Confidential material omitted and filed separately with the Securities and
    Exchange Commission.





                                       30
<PAGE>   31


               -------------------------------------------------
                                   APPENDIX A

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

                         TERMS AND CONDITIONS APPLICABLE
                              TO RESEARCH CONTRACT
                -------------------------------------------------


1.       OBJECT.

         Pursuant to a mutually agreed upon research program which shall be
         definitely established by the Research Committee referred to in Section
         2. hereinafter on terms substantially in accordance with the draft
         research program attached hereto as EXHIBIT+1 (the "RESEARCH PROGRAM"),
         VRI agrees to conduct research works described therein and LICENSEE
         agrees to support and fund such Research Program in accordance with the
         terms and conditions set forth here below.

2.       OVERSIGHT OF THE RESEARCH PROGRAM.

2.1.     OVERSIGHT. The Research Program shall be overseen and monitored by the
         Research Committee as described herein (the "COMMITTEE").

2.2.     MEMBERSHIP. VRI and LICENSEE shall each appoint two (2) persons (or
         such other number of persons as the Parties may determine) to serve on
         the Committee. Such representatives shall be qualified, by reason of
         background and experience, to assess the scientific progress of the
         Research Program. Each Party shall have the right to change its
         representation on the Committee upon written notice sent to the other.

2.3.     CHAIR. The Committee shall be chaired by one representative of
         LICENSEE.

2.4.     RESPONSIBILITIES. The Committee shall have authority to:

         (i)      review and approve the draft Research Program and establish
                  the definitive Research Program;

         (ii)     make recommendations regarding the performance of the Research
                  Program and the conduct of research works pursuant thereto,
                  and monitor performance thereunder;

         (iii)    modify the Research Program as it determines, for each twelve
                  (12) month period during the term thereof;

         (iv)     review any and all proposed publication or communication
                  relating to the Research Program and the results therefrom;






                                       31
<PAGE>   32

         (v)      review any and all proposed filings of patent applications in
                  connection with the Research Program.

2.5.     MEETINGS. The Committee shall meet not less than two (2) times a year
         during the term of the Research Program, at such dates and times as
         agreed to by the Parties. Meetings in person shall normally take place
         at VRI's premises or such other place as may be mutually agreed upon.
         Meetings may be held by telecommunication means. At such meetings, the
         Committee shall discuss the Research Program and the status of
         performance by VRI under the Program, evaluate the results thereof and
         set priorities therefor. The Committee shall prepare written minutes of
         each meeting and a written record of all decisions whether made at a
         formal meeting or not. Such minutes shall incorporate semi-annual
         research reports prepared by VRI.



3.       THE PRINCIPAL INVESTIGATOR.

3.1.     PRINCIPAL INVESTIGATOR. The Principal Investigator of the Research
         Program shall be Dr Kevin KILLEEN, an employee of VRI ("PRINCIPAL
         INVESTIGATOR"). VRI shall consult with LICENSEE regarding any
         replacement of the Principal Investigator, PROVIDED, however, that VRI
         shall have the right to make, and shall make, the final determination
         regarding any such replacement. The Principal Investigator shall be
         appointed as a member of the Committee and may be designated by VRI to
         act on behalf of VRI as co-chair on such Committee.


3.2.     DUTIES. The Principal Investigator shall direct the Research Program
         and coordinate the efforts of other researchers involved in the
         performance of such Program. The Principal Investigator shall sit with
         the Committee as provided in Section 2. hereof, shall contribute to the
         performance of the duties set forth hereunder and shall be afforded the
         opportunity to actively participate in all Committee deliberations. The
         Principal Investigator shall provide reasonably detailed status reports
         of the Research Program to the Committee at six-month intervals, as
         well as at the earliest practicable time whenever, in the Principal
         Investigator's judgment, an invention is created or reduced to
         practice. The Principal Investigator shall devote such time and efforts
         as may be required to fulfill his duties hereunder and to ensure the
         successful administration and coordination of the Research Program.


3.3.     REPLACEMENT. The Principal Investigator may be replaced at any time
         upon the written request of either Party. In such event, or if the then
         existing Principal Investigator is no longer able or is unwilling so to
         serve, the Parties shall endeavour to find a mutually acceptable
         substitute. If no mutually acceptable substitute can be agreed upon
         within a reasonable time, then HPC shall have the right to terminate
         forthwith the Research Program, and effect of such termination shall be
         as provided for in Section 6.2 hereof, it being understood that
         termination of the Research Program shall not entail termination of,
         and shall be without any prejudice whatsoever to, the License
         Agreement.




                                       32
<PAGE>   33
                                                         CONFIDENTIAL TREATMENT


4.       CONDUCT OF RESEARCH PROGRAM.

4.1.     GOOD LABORATORY PRACTICES. The Research Program shall be conducted by
         VRI at VRI's laboratories. VRI shall use all reasonable efforts to
         complete research works in accordance with the said Program. Any
         research work performed by VRI pursuant hereto shall be in compliance
         with current Good Laboratory Practices (cGLP) as applicable in the
         United States of America.

4.2.     LABORATORY NOTEBOOKS. VRI shall cause its employees to maintain
         laboratory notebooks. Such laboratory notebooks shall set forth such
         work in detail, including a clear description of the purposes for which
         the work has been undertaken and the results expected; sufficient
         details, diagrams, plans, sketches and identification of materials
         used, formulations and operating conditions under which the work was
         conducted as may be necessary to understand and reproduce the work
         conducted; identification of any intermediate or final results
         achieved; and if such laboratory notebooks contain any interpretations
         of data, they shall also describe the rough data upon which such
         interpretations have been based. VRI shall further cause its employees,
         agents and permitted subcontractors maintaining such laboratory
         notebooks to have their work corroborated periodically, which
         corroboration shall include at least personal witnessing of the
         notebooks indicating that the witness has read and understood the
         material on the page witnessed on the date that he or she signed it.



5.       FINANCIAL CONDITIONS.

5.1.     SUPPORT COMMITMENT. In consideration of the work performed by VRI
         pursuant to and in accordance with the Research Program, LICENSEE shall
         make available to VRI during the Research Program a maximum of [*] (the
         "Commitment"). The Commitment shall be inclusive of all costs incurred
         by VRI implementing the Research Program.

5.2.     PAYMENTS SCHEDULE. Support payments shall be made by LICENSEE to VRI in
         one single payment within fifteen (15) days of the Effective Date of
         this Agreement.

5.3.     REPORTING. VRI shall report and reconcile budgeted versus actual
         expenditures on a semi-annual basis. Two copies of the semi-annual
         report shall be sent to HPC. Upon reasonable advance request and at
         reasonable times (but not on more than two occasions), HPC shall have
         the right on demand to receive full and true financial information
         regarding any and all matters affecting compliance with Research
         Program and any amounts funded hereunder and to inspect the relevant
         books and records of VRI relating thereto, at HPC expenses, using
         representatives of its choice. VRI's books of account and all necessary
         supporting data shall be kept for at least three (3) years following
         the end of the fiscal year to which each will pertain. In the event
         that amounts funded pursuant hereto exceeds actual




/*/ Confidential material omitted and filed separately with the Securities and
    Exchange Commission.



                                       33
<PAGE>   34

         expenditures incurred by VRI, VRI shall promptly reimburse such excess
         to HPC, unless the Parties mutually agree on an extension of the
         Research Program which would require consummation of such excess.


5.4.     NO CONFLICT WITH RESEARCH PROGRAM. VRI agrees that the Commitment
         provided by LICENSEE shall be applied to the Research Program and may
         not, without LICENSEE prior written approval, be used in support of any
         other research at VRI.

5.5.     TITLE TO EQUIPMENT. VRI shall retain title to any equipment purchased
         with funds provided by LICENSEE under this Agreement, if such purchase
         is mutually agreed upon as part of the Research Program budget.

6.       TERM OF THE RESEARCH PROGRAM.

6.1.     The term of the Research Program shall be twelve (12) months as from
         January 1, 1997, unless terminated earlier upon termination of this
         Agreement in accordance with Article 10 of the License Agreement.

6.2.     HPC shall be entitled to forthwith terminate the Research Program and
         cease funding thereof (i) in the event of disagreement between the
         Parties as to the replacement of the Principal Investigator under
         Section 3.3 hereinabove, and (ii) in the event of a material breach by
         VRI of any VRI's obligations and covenants hereunder. In the event of
         any such termination, VRI shall reimburse HPC of any amounts paid by
         HPC and found in excess of VRI's actual expenditures (reasonable
         termination costs excluded) further to an accounting audit conducted in
         accordance with Section 5.3 above. VRI's right to receive any unpaid
         balance otherwise committed by HPC as support commitment to the
         Research Program pursuant to Section 5.1 hereof shall become forfeited
         and no further payments with respect to Research Program shall be due
         to VRI by HPC. Termination of the Research Program pursuant to this
         Section 6.2. shall not entail termination of, and shall be without any
         prejudice whatsoever to the License Agreement.



7.       CONFIDENTIALITY.

         In order to facilitate the Research Program, either Party may disclose
         confidential or proprietary information owned or controlled by it to
         the other. It is hereby understood and agreed that such information
         shall be deemed "CONFIDENTIAL INFORMATION" as defined in Article 8 of
         the License Agreement and treated as such.

8.       PUBLICATIONS.

         Each Party shall have the right to publish or present the Results of
         the Research Program and announce scientific progress of the Research
         Program, provided such publication, presentation or announcement (and
         any revisions thereof, a "Publication") is submitted to the other Party
         through the Committee at least sixty (60) days prior to submitting it
         to any Third-Party (including any editing person). The other Party
         shall have sixty (60) days after receipt of the draft Publication to
         review




                                       34
<PAGE>   35


         and comment on such draft. Upon notice within such sixty (60) day
         period by the other Party that such Party reasonably believes the
         Publication would amount to the public disclosure of a patentable
         invention upon which a patent application should be filed prior to any
         such disclosure, submission of the concerned Publication to
         Third-Parties shall be delayed for a ninety (90) day period from the
         date of said notice, or for such longer period which may appear
         necessary for appropriately drafting and filing a patent application
         covering such invention. If the other Party reasonably believes that
         the Publication would amount to the public disclosure of such other
         Party's Confidential Information, said other Party may request deletion
         of such information from the proposed Publication. In addition, each
         Party shall duly take into account comments made by the other Party on
         any Publication and shall accept to have employees or others acting on
         behalf of the other Party be mentioned as co-authors on any Publication
         describing results to which such persons will have contributed.

9.       INVENTIONS.

         Ownership of inventions, whether or not patentable, and of any patent
         applications and patents based thereon, which may result from the
         Research Program (the "RESEARCH INVENTIONS") shall be established in
         accordance with the following:

         (i)      Any Research Invention which is solely directed to the VRI
                  Technology and/or VECTOR, per se, shall be owned by VRI and
                  automatically licensed by VRI to HPC subject to and in
                  accordance with the LICENSE, except that if any such invention
                  is patented, the term of the corresponding patent shall not be
                  taken into account to determine the Royalty Term;

         (ii)     Any Research Invention solely directed to an HPC Antigen or an
                  Other Hp Antigen, shall be owned by HPC;

         (iii)    Any Research Invention which is directed to the combination of
                  the VRI Technology and an antigen or antigens or another piece
                  of technology controlled by HPC rather than antigens in
                  general, shall be jointly owned by VRI and HPC and be
                  considered a Joint Invention. VRI's interest in such Joint
                  Invention shall be deemed automatically licensed by VRI to HPC
                  subject to and in accordance with the LICENSE, except that if
                  any such invention is patented, the term of the corresponding
                  patent shall not be taken into account to determine the
                  Royalty Term. Except for the rights granted to HPC in the
                  Field of Use under the LICENSE, neither Party shall exploit a
                  Joint Invention without the prior agreement in writing of the
                  other Party, provided VRI may request HPC to enter into good
                  faith negotiations if VRI wishes to exploit any such Joint
                  Invention outside the Field of Use or within the scope of the
                  non-exclusive LICENSE.

         (iv)     Any Research Invention which is directed to the combination of
                  VRI Technology and to antigens in general shall be owned by
                  VRI and automatically licensed by VRI to HPC, subject to and
                  in accordance with the LICENSE, except that if any such
                  invention is patented, the term of the corresponding patent
                  shall not be taken into account to determine the Royalty Term.




                                       35
<PAGE>   36
                                                         CONFIDENTIAL TREATMENT


                -----------------------------------------------
                                   APPENDIX B

                                   -----------

                       TERMS AND CONDITIONS APPLICABLE TO
                                  VECTOR SUPPLY
                -----------------------------------------------


1.       THE SUPPLY AGREEMENT. VRI has stated to LICENSEE its current intention
         to establish itself as a manufacturer of the VECTOR. Provided VRI can
         reasonably demonstrate that it shall be able to timely manufacture
         VECTOR under current Good Manufacturing Practice at competitive cost in
         sufficient quantities, LICENSEE shall purchase from VRI LICENSEE's
         requirements for VECTOR for use in the manufacture of PRODUCTS under
         the terms and conditions of a supply agreement (the "SUPPLY
         AGREEMENT"), which agreement shall be negotiated in good faith in a
         timely fashion by the Parties hereto so as to become effective at least
         six months before LICENSEE's expected First Commercial Sale of
         PRODUCTS. The Parties agree to negotiate in good faith in a timely
         fashion the detailed terms and conditions of the Supply Agreement which
         shall include at a minimum the following terms and conditions set forth
         in this Article 1, as well as such other terms and conditions as may be
         agreed upon by the Parties.


2.       VECTOR REQUIREMENTS. The Supply Agreement shall provide that VRI shall
         manufacture or have manufactured and LICENSEE shall purchase from VRI,
         LICENSEE's entire requirements of VECTOR (clinical lots as well as
         commercial lots) for PRODUCTS and that LICENSEE shall purchase such
         VECTOR for its own use in manufacturing PRODUCTS only and shall not be
         permitted to sell or re-sell VECTOR to any Third-Party.

3.       SPECIFICATIONS. The Supply Agreement shall provide for (i)
         specifications that VRI shall be obligated to comply with; (ii)
         quality control criteria and procedures; and (iii) LICENSEE's
         reasonable acceptance criteria for the VECTOR.

4.       FORECASTS AND ORDERS. The Supply Agreement shall provide for the
         establishment of reasonable rolling forecasts and placement of orders
         which shall take into account VRI's need to rationally plan its
         manufacturing of VECTOR consistent with its other manufacturing
         obligations.

5.       PRICE. The price of VECTOR shall be negotiated in good faith by the
         Parties and set forth in the Supply Agreement, but in no event shall
         such price be for less than [*].





/*/ Confidential material omitted and filed separately with the Securities and
    Exchange Commission.



                                       36
<PAGE>   37


6.       BACK-UP INVENTORIES. Pursuant to the Supply Agreement, VRI shall agree
         to supply, and LICENSEE shall agree to maintain inventory of VECTOR in
         its own facility sufficient to meet its forecasted needs.

7.       WARRANTIES. Pursuant to the Supply Agreement, VRI shall warrant that
         (i) VECTOR at the time of delivery shall meet the specifications
         referred to in Section 3. hereinabove; (ii) VECTOR shall be
         manufactured in accordance with current Good Manufacturing Practices in
         effect in the country where it is manufactured or in compliance in all
         material respects with the principles of the current Good Manufacturing
         Practices in effect in any other country where PRODUCTS are
         manufactured and/or sold (if more stringent than cGMP first referred
         above) and any relevant establishment and product licenses issued by
         any public health authority having jurisdiction. LICENSEE shall inform
         VRI of the countries in which PRODUCT is to be licensed to be sold and
         of any and all Agency(ies) responsible in such countries. Upon request,
         LICENSEE shall provide VRI with information regarding the regulatory
         requirements in each such country. VRI SHALL DISCLAIM ANY OTHER
         WARRANTIES, EXPRESS OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF
         MERCHANTABILITY AND FITNESS.

8.       QUALITY AUDIT. Pursuant to the Supply Agreement, VRI shall permit
         LICENSEE, upon reasonable notice and at reasonable times, at LICENSEE's
         expense, to audit in cooperation with VRI's personnel production,
         packaging, quality control and forwarding facilities of VRI and any of
         its significant suppliers as they relate to VRI's manufacturing
         responsibilities under the Supply Agreement.

9.       ADVERSE EVENTS REPORTING. Under the Supply Agreement, the Parties shall
         establish a procedure for monitoring and reporting adverse drug
         experiences, consistent with Article 15 of the License Agreement.

10.      ASSURANCE OF SUPPLY. Under the terms of the Supply Agreement, LICENSEE
         and VRI shall cooperate to anticipate LICENSEE's reasonable long-term
         requirements for VECTOR, and VRI shall take reasonable measures to
         assure that LICENSEE's reasonable requirements can be met, which
         measures may include the qualification of more than one manufacturing
         facility (including one such facility that may be operated by LICENSEE
         or an Affiliate of LICENSEE, in which case VRI shall transfer
         manufacturing Know-how in accordance with Section 11 hereinafter)
         and/or maintenance of safety stocks of VECTOR as provided for in
         Section 6 hereof.



11.      TRANSFER OF MANUFACTURING TECHNOLOGY.

         The Supply Agreement shall contain provisions for the compulsory
         transfer of Manufacturing Know-How from VRI to HPC under certain
         circumstances such as, but not necessarily limited to, durable failure
         to supply by VRI, VRI's Affiliates or contractors, VRI's material
         breach of the Supply Agreement or VRI's bankruptcy.






                                       37
<PAGE>   38

12.      NO ASSIGNMENT ; NO SUB-CONTRACT. VRI shall neither assign nor
         sub-contract any part of its rights and obligations under this APPENDIX
         B, or any part of its manufacturing responsibility under the Supply
         Agreement, to any third Party without the prior written agreement of
         LICENSEE which shall not unreasonably withheld.

13.      LIABILITIES, INDEMNIFICATION AND INSURANCE. The Supply Agreement shall
         include provisions relating to liabilities, indemnification and
         insurance substantially similar to the provisions of the Indemnity
         Agreement herewith attached as EXHIBIT 1.



                 ---------------------------------------------
                                    EXHIBIT 1

                                   ----------

                               INDEMNITY AGREEMENT
                 ---------------------------------------------


WHEREAS, HPC (hereinafter called "Purchaser") and VRI (hereinafter called
"Supplier") have entered into a License Agreement (the "License") relating to
the use of a certain VECTOR (the "VECTOR") known as VibrioVec for use as a
delivery system in vaccines against Helicobacter pylori infections, dated as of
December 1, 1997;

WHEREAS, pursuant to the License, Supplier has agreed to sell, and Purchaser has
agreed to purchase, certain quantities of VECTOR, under terms and conditions set
forth in short form in the relevant provisions contained in APPENDIX B of the
License and to be finally established in a Supply Agreement to be negotiated in
good faith in a timely manner by the parties hereto;

WHEREAS, Purchaser is planning to enter into human clinical trials using VECTOR;

WHEREAS, in order to allow these actions to be timely undertaken, the parties
have agreed to set-up terms and conditions applicable to liabilities and
indemnification in connection with the early supply of clinical lots of VECTOR
which have previously been supplied to Purchaser, in advance of entering into
the definitive Supply Agreement.

NOW, THEREFORE, in consideration of the premises herein and for other good and
valuable consideration, the parties hereto agree as follows:

1.       PURPOSE.

         This Agreement shall set forth the terms and conditions under which
         Purchaser shall provide and maintain insurance coverage and indemnify
         Supplier in certain circumstances in connection with the use of VECTOR
         by Purchaser in human clinical trials.




                                       38
<PAGE>   39

2.       INSURANCE.

         Each party, at its own expense, will maintain, with insurers which are
         rated A or better by A.M. BEST, a General Product Liability,
         Environmental and, in the case of Purchaser, Clinical Trial insurance
         program(s) in an amount commensurate with the risks incurred. Purchaser
         will cause (a) Supplier to be named as an additional insured under
         Purchaser's General & Product Liability and Environmental Liability
         insurance policies (but under those policies only and with coverage
         limited to Claims as defined in Section 4 hereof), (b) such insurance
         to be designated as primary to any insurance which may be carried by
         Supplier, and (e) such insurance to provide that it can only be
         cancelled or materially altered upon not less than thirty (30) days
         notice to Supplier. Purchaser shall not assert against Supplier and
         hereby waives any and all claims against Supplier for losses, damages,
         liability, judgments, costs and expenses (including attorney's fees)
         imposed upon or incurred by Purchaser as a result of or arising out of
         any claim covered by such insurance to the extent of such coverage and
         to the extent Purchaser will have agreed to indemnify Supplier pursuant
         to Section 4 hereinafter.

3.       INSURANCE CERTIFICATES.

         Prior to issuing the first purchase order to Supplier and from time to
         time thereafter as reasonably required by Supplier, Purchaser shall
         furnish Supplier with (an) insurance certificate(s) evidencing
         compliance with Insurance Section above, and reciprocally.

4.       INDEMNITY.

         Notwithstanding the existence or lack of insurance, Purchaser shall, at
         its sole cost and expense, defend Supplier from any and all claims,
         demands, actions or causes of action, at law or in equity (including
         but not limited to claims by Purchaser's employees and customers and
         including an environmental liability) (a "Claim") and indemnify and
         hold Supplier harmless from all damages, liabilities, losses, costs,
         judgments, orders, assessments, interest, penalties, fines, settlement
         payments, costs and expenses (including, without limitation, reasonable
         attorneys fees and other investigation and defense costs and expenses)
         incurred by Supplier which arise out of or result in any way from
         bodily injury (including death) or property damage, however arising out
         of, or related in any way, to Purchaser's possession, use, sale,
         distribution, processing, shipment, storage or disposal of the VECTOR
         or any derivative thereof sold or otherwise transferred by Supplier to
         Purchaser for the purpose described in the preamble to this Agreement.
         Purchaser shall have the duty to defend, indemnify and hold Supplier
         harmless against any actual or alleged negligence by Supplier. In the
         event that Purchaser fails to promptly and diligently investigate and
         defend or settle any Claim then Supplier shall have the right, at
         Purchaser's cost, expense and risk, from that time forward to have sole
         control of the defense of the Claim and all negotiations for its
         settlement or compromise.

         Notwithstanding the foregoing, the INDEMNITY provided for hereinabove
         shall not apply to the extent that the Claim arises out of, is based
         upon or results from the gross negligence or willful misconduct (which
         shall include misrepresentation or concealment of data relating to
         toxicity of VECTOR) of Supplier, or an event having occurred before




                                       39
<PAGE>   40

         the time that title to VECTOR (or to any shipment or unit thereof)
         passes to Purchaser, in which cases Supplier shall defend, indemnify
         and hold Purchaser harmless in the same manner and to the same extent
         than provided for hereinabove where Purchaser is the indemnifying
         party, and PROVIDED further that, in any event, the INDEMNITY provided
         for hereinabove shall not apply to the extent the Claim is a claim for
         environmental liability arising out of, based upon or resulting from an
         event occurring at a Supplier's facility or a facility of a supplier's
         sub-contractor, or at any other place (including during transportation)
         prior to the time title to VECTOR (or to any shipment or unit thereof)
         passes to Purchaser.

         The Indemnity provided for herein shall be limited to Claims relating
         to units of VECTOR sold or otherwise transferred by Supplier to
         Purchaser for the purpose described in the preamble to this Agreement,
         as identified in the invoices and/or control certificates and other
         commercial and pharmaceutical documentation issued by Supplier to
         Purchaser along with the delivery of such units of VECTOR.

5.       COSTS & EXPENSES.

         The indemnities in INDEMNITY Paragraph of this Agreement include all
         costs and expenses reasonably required to investigate and to defend any
         such claim or action, any amount paid or required to be paid to settle
         such claim or action, or any amount paid or required to be paid to
         settle such claim or action, or any amount finally awarded by a court
         as damages or otherwise in any such action, provided that neither party
         will have an obligation to pay or to reimburse the other party for the
         amount of any internal expenses (including, but not limited to,
         compensation paid to its employees) that it may incur in connection
         with its cooperation in the investigation and/or defense of such claim
         or action.

6.       LIMITATION OF LIABILITY.

         IN NO EVENT SHALL ANY PARTY HAVE ANY LIABILITY TO THE OTHER PARTY
         HEREUNDER OR OTHERWISE FOR ANY LOSS OF PROFITS, COST OR COVER OR ANY
         SPECIAL, CONSEQUENTIAL, INCIDENTAL, INDIRECT OR PUNITIVE DAMAGES,
         HOWEVER CAUSED, WHETHER BY THE OTHER PARTY'S BREACH OF ANY EXPRESS OR
         IMPLIED WARRANTY, NEGLIGENCE, STRICT LIABILITY UNDER LAW OR OTHERWISE.

7.       SURVIVAL.

         The provisions of this Agreement shall survive the expiration and/or
         termination of this Agreement, unless this Agreement is superseded by
         the Supply Agreement, in which case the provisions relating to
         Liabilities and Indemnification contained in said Supply Agreement will
         supersede this Agreement.




                                       40
<PAGE>   41
                                                         CONFIDENTIAL TREATMENT



CONFlDENTIAL
Exhibit I to Appendix A


                                RESEARCH PROPOSAL
            APPLICATION OF VIBRIOVEC(TM) AND ATTENUATED SALMONELLA AS
                           LIVE ORAL VECTORS FOR PM-O
                         PROPRIETARY H. PYLORI ANTIGENS





[*]












/*/ Confidential material omitted and filed separately with the Securities and
    Exchange Commission. A total of 8 pages have been omitted from this
    Exhibit 1 to Appendix A.






                                       41