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April 22 1999                                          Novavax/Cantab - page: 1

                                  NOVAVAX, INC.

                                     - and -

                     CANTAB PHARMACEUTICALS RESEARCH LIMITED

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                                LICENCE AGREEMENT

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April 22 1999


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April 22 1999                                          Novavax/Cantab - page: 2


THIS AGREEMENT is made the                       day of         1999
BETWEEN

 (1)     NOVAVAX, INC. a company incorporated under the law of the State of
         Delaware, whose principal place of business is at Suite C, 8320
         Guilford Road, Columbia, MD 21046, USA (together with its subsidiaries
         (including without limitation its wholly-owned subsidiaries Micro-Pak,
         Inc. and Micro Vesicular Systems Inc), "Novavax"); and

 (2)     CANTAB PHARMACEUTICALS RESEARCH LIMITED (Company number 2270217) a
         company incorporated under the laws of England whose registered office
         is at 310 Cambridge Science Park, Milton Road, CB4 0WG ("Cantab").

RECITALS

 (A)     Pursuant to an agreement of 23 December 1997 between Novavax and
         Cantab, Novavax granted Cantab an exclusive option to acquire a
         worldwide exclusive licence under the Novavax IP (as defined herein).

 (B)     Cantab has exercised that option and Novavax (including Novavax's
         wholly-owned subsidiaries Micro-Pak, Inc., and Micro Vesicular Systems,
         Inc., which is/are registered owner(s) of patent rights included in the
         Novavax IP as hereinbelow defined, and which have endorsed their
         consent to the transaction hereby effected and their agreement to be
         bound thereby insofar as their proprietary interests are affected)
         hereby grants Cantab an exclusive worldwide licence to the Novavax IP
         on the terms and conditions set out herein.

IT IS AGREED AS FOLLOWS:-

 1.      DEFINITION AND INTERPRETATION

 1.1     In this Agreement and in the Schedules to this Agreement the following
         words and phrases shall have the following meanings unless the context
         requires otherwise:-

 1.1.1   "Affiliate" - any company, partnership or other entity which directly
         or indirectly Controls, is Controlled by or is under common Control
         with, either Party including as a Subsidiary or Holding Company.

 1.1.2   "Agreement" - this agreement and any and all schedules, appendices and
         other addenda to it as may be varied from time to time in accordance
         with the provisions of this agreement.

 1.1.3   "Business Day" - 9.30am to 5.30pm (local time at Cantab offices) on a
         day other than a Saturday, Sunday, bank or other public holiday in
         England and Wales.

 1.1.4   "Cantab Net Sales" - shall mean all sums received by Cantab or an
         affiliate of Cantab upon the sale by Cantab or such affiliate of any
         Licensed Product (net only of any value added or other taxes thereon
         and of deductions for freight charges, insurance, allowances


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April 22 1999                                          Novavax/Cantab - page: 3

         actually made for returned defective products and customary trade,
         quantity or cash discounts to non-affiliated customers to the extent
         actually allowed and taken);

 1.1.5   "Commencement Date" - the date of execution of this Agreement.

 1.1.6   "Competent Authority" - any local or national agency, authority,
         department, inspectorate, minister, ministry official, parliament or
         public or statutory person (whether autonomous or not) of or of any
         government of any country having jurisdiction over either any of the
         activities contemplated by this Agreement or the Parties, including the
         European Commission and the European Court of Justice.

 1.1.7   "Confidential Information" - in the case of obligations on Cantab shall
         mean Novavax IP, in the case of obligations on Novavax shall mean
         Cantab IP and in the case of obligations on both Cantab and Novavax
         shall mean trade secrets, know how or confidential information relating
         to the business affairs or finances of the other supplied or otherwise
         made available to them or coming into their possession in relation to
         the performance of this Agreement.

 1.1.8   "Control" - the ownership of more than 50% of the issued share capital
         or legal power to direct or cause the direction of the general
         management and policies of the Party in question.

 1.1.9   "Directive" - includes any present or future directive, regulation,
         requirement, instruction, direction or rule of any Competent Authority
         including any amendment, extension or replacement thereof then in
         force.

 1.1.10  "Field" - the use of the Novasomes Adjuvant in the development and
         subsequent exploitation of an immunopharmaceutical comprising antigenic
         determinants of human papillomavirus for the prevention or treatment of
         cervical disease including CIN (cervical intraepithelial neoplasia),
         and of an immunopharmaceutical comprising antigenic determinants of
         human papillomavirus type 16 or 18 for any other treatment purposes for
         which that immunopharmaceutical may be used;

1.1.11   "First Commercial Sale" - the first commercial sale by Cantab or its
         sub-licensees or distributors, in any country, of Licensed Product
         after grant of required Marketing Authorisation and pricing approval
         has been granted by the appropriate Regulatory Authority or other
         Competent Authority.

 1.1.12  "Force Majeure - in relation to either Party any event or circumstances
         which is beyond the reasonable control of that Party which event that
         Party could not reasonably be expected to have taken into account at
         the date of this Agreement and which results in or causes the failure
         of that Party to perform any or all of its obligations under this
         Agreement, including act of God, lightning, fire, storm, flood,
         earthquake, accumulation of snow or ice, lack of water arising from
         weather or environmental problems, strike, lockout or other industrial
         disturbance, act of the public enemy, war declared or undeclared,
         threat of war, terrorist act, blockade, revolution, riot, insurrection,
         civil commotion, public demonstration, sabotage, act of vandalism,
         prevention from or hindrance in obtaining in any way materials energy
         or other supplies, explosion, fault or failure of plant or machinery
         (which could not have been prevented by good industry practice),
         Directive or requirement of a Competent Authority governing either
         Party provided that lack of funds shall not be interpreted as a cause
         beyond the reasonable


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April 22 1999                                          Novavax/Cantab - page: 4



         control of that Party.

 1.1.13  "Half Year" - shall mean each six month period in any year ending on 30
         June or 31 December, and "Half Yearly" shall be construed accordingly.

 1.1.14  "Insolvency Event" - in relation to Cantab, means any one of the
         following:
         (a) a notice shall have been issued to convene a meeting for the
         purpose of passing a resolution to wind up Cantab or such a resolution
         shall have been passed; or
         (b) a resolution shall have been passed by Cantab's directors to seek a
         winding up or administration order or a petition for a winding up or
         administration order shall have been presented against Cantab's or such
         an order shall have been made; or
         (c) a receiver, administrative receiver, receiver and manager, interim
         receiver, custodian, sequestrator or similar officer is appointed in
         respect of Cantab or over a substantial part of its assets or any third
         party takes steps to appoint such an officer in respect of Cantab or an
         encumbrancer takes steps to enforce or enforces its security; or
         (d) a proposal for a voluntary arrangement shall have been made in
         relation to Cantab under Part I Insolvency Act 1986; or
         (e) a step or event shall have been taken or arisen outside the United
         Kingdom which is similar or analogous to any of the steps or events
         listed at (a) to (d) above; or
         (f) that Cantab proposes to readjust, reschedule or defer all or
         substantially all of its indebtedness, or proposes or makes any general
         assignment, composition or arrangement with or for the benefit of all
         or some of its creditors or makes or suspends or threatens to suspend
         making payments to all or some of its creditors or submits to any type
         of voluntary arrangement; or
         (g) Cantab is deemed to be unable to pay its debts within the meaning
         of Section 123 Insolvency Act 1986.

 1.1.15  "Know-How" - unpatented technical and other information which is not in
         the public domain including information comprising or relating to
         concepts, discoveries, data, designs, formulae, ideas, information
         relating to materials, inventions, methods, models, assays, research
         plans, procedures, designs for experiments and tests and results of
         experimentation and testing (including results of research or
         development) processes (including manufacturing processes,
         specifications and techniques), laboratory records, chemical,
         pharmacological, toxicological, clinical, analytical and quality
         control data, trial data, case report forms, data analyses, reports,
         manufacturing data or summaries and information contained in
         submissions to an information from ethical committees and regulatory
         authorities, but at any time does not include any matter that has
         become and remains available to the public through no wrongful act or
         omission to act of the party (or its sublicensee or distributor) owing
         obligation to the other in respect of such matter as part of Know-How,
         as from the time when that matter becomes available to the public.
         Know-How includes documents containing Know-How. Information will not
         be excluded from being Know-How hereunder by reason only of the fact
         that it becomes available to the public through a wrongful act or
         omission to act of a Party hereto or a sublicensee or distributor of a
         Party hereto. The fact that an item is known to the public shall not be
         taken to exclude the possibility that a compilation including the item,
         and/or a development relating to the item, is (and remains) not known
         to the public. Know-


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April 22 1999                                          Novavax/Cantab - page: 5


         How includes any rights including copyright, database or design rights
         protecting such Know-How.

1.1.16   "Licensed IP" - the Licensed Patent Rights and the Licensed Know-How.

1.1.17   "Licensed Know-How" - any and all Know How within the Field which is
         owned by or licensed to Novavax at the Commencement Date or which
         becomes owned by or licensed to Novavax during the term of this
         Agreement, in either case insofar as it continues to be Know-How.

 1.1.18  "Licensed Patent Rights" - the Patent Rights listed in Schedule 1 and
         any Patent Rights claiming or covering or otherwise based on inventions
         forming part of the Licensed Know How.

 1.1.19  "Licensed Product" - a product made for use in the Field and either
         sold or to be sold for use in the Field, incorporating or using any
         part of the Licensed IP, such that in the absence of the licence
         granted by this agreement Cantab's (or Cantab's sublicensee's or
         distributor's) acts in relation to manufacture, use or sale of such
         product would constitute an infringement of the Licensed IP;

 1.1.20  "Major Markets" - United States, United Kingdom, France, Germany,
         Spain, Italy and Japan.

 1.1.21  "Marketing Authorisation" - any approval required from a Regulatory
         Authority to market and sell Licensed Product in any country.

 1.1.22  "Materials Transfer Agreement" - the materials transfer agreement
         between the Parties dated 16 May 1997.

 1.1.23  "Net Cantab Receipts" - shall mean all sums received by Cantab upon the
         sale of any Licensed Product by any sublicensee or otherwise received
         under the terms of any sublicense agreement authorised hereunder.

 1.1.24  "Novasomes Adjuvant" - the adjuvant and associated technology specified
         in the Licensed Patent Rights with respect to Paucilamellar
         non-phospholipid liposomes.

 1.1.25  "Novavax Materials" - physical samples of Novasomes Adjuvant and other
         compounds supplied by Novavax to Cantab under the Materials Transfer
         Agreement or corresponding term of this Agreement.

 1.1.26  "Parties" - Cantab and Novavax.

 1.1.27  "Patent Rights" - patent applications or patents, author certificates,
         inventor certificates, utility certificates, improvement patents and
         models and certificates of addition and all foreign counterparts of
         them and includes any divisions, renewals, continuations,
         continuations-in-part, extensions, reissues, substitutions,
         confirmations, registrations, revalidation or additions of or to them,
         as well as any supplementary protection certificate in respect of them.


 1.1.28  "Regulatory Authority" - any national, supranational (e.g., the
         European Commission, the Council of the European Union, the European
         Agency for the Evaluation of Medicinal Products or the FDA), regional,
         state or local regulatory agency, department, bureau, commission,
         council or other governmental entity other in each country of the
         Territory involved in the granting of Marketing Authorisation for the
         Licensed Product.

 1.1.29  "Subsidiary or Holding Company" - as relates to Cantab, shall have the
         meaning ascribed to such expressions by Section 736 of the Companies
         Act 1985 (as amended),

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April 22 1999                                          Novavax/Cantab - page: 6

         and as it relates to Novavax, shall mean any legal entity (such as a
         corporation, partnership, or limited liability company) that is
         controlled by, under common control with, or controls Novavax. For the
         purpose of this definition, control means (i) beneficial ownership of
         at least 50% of the voting securities of a corporation or other
         business organisation with voting securities or (ii) a fifty percent or
         greater interest in the net assets or profits of a partnership or other
         business organisation without voting securities.

 1.1.30  "Valid Claim" - either:
         (a) a claim of an issued and unexpired patent included within Patent
         Rights, 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; or
         (b) a claim of a pending patent application included within Patent
         Rights, which claim was filed in good faith and has not been abandoned
         or finally disallowed without the possibility of appeal or refiling of
         said application.

 1.2     In this Agreement:

 1.2.1   unless the context otherwise requires all references to a particular
         Clause, paragraph or Schedule shall be a reference to that Clause,
         paragraph or Schedule, in or to this Agreement as the same may be
         amended from time to time pursuant to this Agreement;

 1.2.2   a table of contents and headings are inserted for convenience only and
         shall be ignored in construing this Agreement;

 1.2.3   unless the contrary intention appears words importing the masculine
         gender shall include the feminine and vice versa and words in the
         singular include the plural and vice versa;

 1.2.4   unless the contrary intention appears words denoting persons shall
         include any individual, partnership, company, corporation, joint
         venture, trust, association, organisation or other entity, in each case
         whether or not having separate legal personality;

 1.2.5   reference to the words "include" or "including" are to be construed
         without limitation to the generality of the preceding words; and

 1.2.6   reference to any statute or regulation includes any modification or
         re-enactment of that statute or regulation.

 2.      GRANT OF LICENCE

 2.1     Subject to this Agreement and in consideration of all of its terms,
         Novavax grants Cantab an exclusive world-wide licence to develop, use,
         have used, manufacture, have made, exploit, market, sell and have sold
         Licensed Products solely for use in the Field and to use the Licensed
         IP within the Field. Subject to Cantab's rights under this Agreement,
         Novavax shall retain all rights not expressly granted in this Clause
         2.1. The licence shall be for the period in which any Licensed IP shall
         remain valid and enforceable (the "License Period"), unless earlier
         terminated as provided in Section 10


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April 22 1999                                          Novavax/Cantab - page: 7

         hereof.

 2.2     Cantab shall be entitled to sublicense all or any part of its rights
         granted under Clause 2.1 above to third parties in such manner as it
         considers appropriate: Cantab shall promptly provide Novavax with
         information relating to the terms of such sublicence agreement and
         arrangements made in pursuance of such sublicence agreement to the
         extent appropriate to enable Novavax to ascertain Novavax's legal
         rights and financial expectations and enforce its legal rights arising
         in consequence of such sublicence, and such information shall without
         limitation include: parties to the agreement and its date of execution;
         the scope of the sublicence, as it relates to Licensed IP, including
         technical and geographical scope and whether the scope include the
         right to make, use and/or sell; the nature of measures taken by the
         sublicence terms to protect confidentiality of Novavax's Know-How and
         other confidential, proprietary or nonpublic information; and
         information relating to the development plan to be undertaken under
         such sublicense agreement, sufficient to ascertain the measures to be
         taken to achieve the milestones referred to in this agreement and to
         achieve and advance product marketing and sales.

 2.3     Novavax shall during the term of this Agreement promptly notify Cantab
         of all information relating to improvements and/or developments to the
         Novasomes Adjuvant, the Licensed IP (including the legal status of the
         Licensed Patent Rights) or their application which are of relevance
         within the Field to the manufacturing or marketing of Licensed Product
         and any such improvements or developments shall form part of the
         Licensed IP licensed to Cantab free of any further charge or payment.

 2.4     Novavax agrees to deliver, at the request and administrative expense of
         Cantab, such documents as may reasonably be necessary to permit Cantab
         to record its licensee interest in the Licensed IP, provided That no
         such filing shall contain any confidential proprietary or non-public
         information of Novavax, and Cantab shall take all action necessary to
         ensure that no right title or interest in any licensed IP vests in
         Cantab by such recordal except the licence granted Clause 2.1 hereof,
         and Cantab shall in the event of termination in whole or in part of
         such licence, (upon request of Novavax and at Cantab's administrative
         expense) execute or procure for Novavax the execution of and file all
         such documents as may reasonably be necessary to record the termination
         of any such rights granted to Cantab under this Agreement with any
         relevant registry or agency.

 3.      FEES

 3.1     In consideration of the licence granted to Cantab under Clause 2 Cantab
         will pay to Novavax the following:

 3.1.1   US$ 75,000 on the Commencement Date; and

 3.1.2   US$ 75,000 on the first anniversary of the Commencement Date
         provided that such licence fees set out in Clauses 3.1.1 and 3.1.2 will
         be non-refundable


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         and not subject to deduction or set-off for any reason against any
         amounts owing to Novavax, including future royalties.

 3.1.3   US$ 25,000 upon the execution of the first sub-licence in the United
         States of America;

 3.1.4   US$ 25,000 upon the execution of the first sub-licence in the United
         Kingdom or the European Union;

 3.1.5   US$ 12,500 upon the execution of the first sub-licence in Japan; and

 3.1.6   US$ 15,000 upon the execution of the first sub-licence in any country
         outside the USA, the European Union and Japan;
         provided that all such fees set out in Clauses 3.1.3 to 3.1.6 shall be
         credited against and deducted from royalties payable pursuant to
         paragraph 3.3.

 3.2     In addition to the fees set out in Clause 3.1, Cantab shall pay to
         Novavax the following milestone fees:-

 3.2.1   US$ 50,000 upon the earlier of:  (a) the date of entry of the first
         patient into a Phase I/lI dose ranging study or the equivalent in any
         other country carried out by or on behalf of Cantab or its sublicensee;
         (b) 6 months after completion of a Phase I study or the equivalent in
         any other country carried out by or on behalf of Cantab or its
         sublicensee; or (c) 30 June, 2000;

 3.2.2   US$ 50,000 upon the date of the first patient into a Phase II study or
         the equivalent in any other country carried out by or on behalf of
         Cantab or its sublicensee;

 3.2.3   US$ 75,000 upon the date of the first patient into a pivotal efficacy
         clinical trial in humans or the equivalent in any other country carried
         out by or on behalf of Cantab or its sublicensee; and

 3.2.4   US$ 100,000 upon the first PLA filing by or on behalf of Cantab or its
         sublicensee of a Licensed Product anywhere, or the equivalent in any
         country.

         All such milestone fees described in this Clause 3.2 shall be credited
         against and deducted from any royalties payable pursuant to Clause 3.3.

         Provided that the deduction actually made in any one year of royalty
         account is not more than $50,000.

 3.3     Cantab shall also pay Novavax the following royalties in respect of
         sales of Licensed Product made during the Royalty Period (payable
         within 30 days of the end of each Half Year for sales effected in the
         preceding Half Year):

 3.3.1   10% of Net Cantab Receipts on all sales of Licensed Product effected by
         any sublicensee;

 3.3.2   2% of Cantab Net Sales on all sales of Licensed Product effected by
         Cantab or an affiliate of Cantab, or by a distributor of Cantab or of
         an affiliate of Cantab; Such royalties to continue to be payable in
         respect of sales of Licensed Product on a country by country basis
         until the last to expire of any Licensed Patent Rights in respect of
         such country ("Royalty Period").


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 3.4     Minimum annual fees in line with standard industry norms for minimum
         royalties (but in any event not exceeding US$ 300,000 pa for the first
         12 month period commencing 1st January after the date of launch of a
         Licensed Product and for each subsequent calendar year) shall be
         payable in respect of each calendar year after First Commercial Sale of
         a Licensed Product, in respect of the Major Markets for the period in
         which royalties shall continue to be payable in respect of Licensed
         Product into such Major Markets at a rate to be negotiated in good
         faith prior to commercial launch of a Licensed Product by reference to
         anticipated and forecast sales of Licensed Product. For the
         abovementioned first 12 month period and for each of the three next
         following 12 month periods thereafter the minimum annual royalty shall
         be $50,000 per 12 month period.

 3.5     Cantab shall and shall ensure that its Affiliates and other
         sub-licensees shall keep true and accurate records and books of account
         containing all data necessary for the calculation of the amounts
         payable by it to Novavax pursuant to this Agreement. Those records and
         books of account shall be kept for six years following the end of the
         calendar year to which they relate and shall, upon reasonable notice
         having been given by Novavax, be open on Business Days for inspection,
         under terms of confidentiality, by Novavax's accountants or by an
         independent firm of accountants appointed by agreement between the
         Parties. In the absence of any fraud, obvious error or in connection
         with the payment of taxes or other third party investigations, or
         actions or claims, any such examination shall take place not later than
         two years following the expiration of the period to which it relates
         and there shall be no more than one examination per year.  The cost of
         the inspection shall be the responsibility of Cantab if the certificate
         is shown to have underestimated the monies payable to Novavax by more
         than two percent and the responsibility of Novavax otherwise. Following
         any such certification the Parties shall make any adjustments necessary
         in respect of the monies already paid to Novavax in relation to the
         period in question.

 3.6     Within 60 days of the end of each Half Year, Cantab shall prepare a
         statement which shall show on a Product by Product and a country by
         country basis for the previous Half Year, all monies due to Novavax
         under this Agreement with respect to such Half Year period, including
         payments due under Clause 3.3.  That statement shall be submitted to
         Novavax within 60 days of the end of the period to which it relates
         together with remittance for monies due to Novavax, if any.

 3.7     All payments to Novavax under this Agreement shall be made in US
         Dollars to the account of Novavax at CITIBANK FSB WASHINGTON, sort code
         ABA# 254070116, account no. # 17511640, in the name of Novavax, Inc.,
         by telegraphic transfer.

 3.8     Where revenues are received from sales of Licensed Product or payments
         made under sublicense agreements, and for purposes of calculating the
         Net Cantab Sales and Net Cantab Receipts for purposes of this Section
         3, in a currency other than US Dollars, the


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April 22 1999                                          Novavax/Cantab - page: 10

         rate of exchange to be used for converting such other currency into US
         Dollars, shall be the rate published in the Wall Street Journal under
         the heading "Currency Trading, Exchange Rates, 135$ Equiv." for the
         last business day of the period to which the calculation applies.

 4.      SUPPLY

         It is agreed that the provisions, in regard to supply and purchase, of
         section 4 in Schedule 2 (form of licence) to the Option Agreement shall
         continue to apply until further agreement between the Parties.

 5.      INTELLECTUAL PROPERTY

 5.1     The Licensed Patent Rights shall remain vested in Novavax. Novavax
         shall at Novavax' cost and expense be solely responsible for the
         prosecution and maintenance of the Licensed Patent Rights and for the
         conduct of any claims or proceedings relating to it including any
         interference or opposition proceedings. Should Novavax decide at any
         time that it does not wish to prosecute or maintain any of the Licensed
         Patent Rights it shall notify Cantab in writing and Cantab shall have
         the right, insofar as any such patent is not maintained by Novavax or
         by a party in privity with Novavax having a right to maintain the same,
         to take-over at its own cost and expense the prosecution and
         maintenance of the Licensed Patent Rights or part thereof upon giving
         written notice to Novavax within 30 days of the date of Novavax'
         notice.

 5.2     Each of Novavax and Cantab shall as soon as practicable after it
         becomes aware thereof give to the other in writing reasonable
         particulars of any use or proposed use by another person which in that
         Party's view amounts to or might amount to an infringement of the
         Licensed Patent Rights. Novavax may, but shall not be obliged to, at
         its own cost and expense enforce and defend the Licensed Patent Rights.
         Where Novavax does, it shall notify Cantab and Cantab shall lend its
         name to any infringement proceedings and shall sign any documents that
         Novavax reasonably requests in relation to any such activity or
         proceedings and shall give Novavax all reasonable assistance requested
         by Novavax in relation to them (at no charge or expense to Novavax,
         other than with respect to reasonable out-of-pocket expenses, but
         Cantab shall not be bound to incur unreasonable expenses). Novavax
         shall keep Cantab informed of the progress of such enforcement or
         defence of the Licensed Patent Rights. If Novavax succeeds in any such
         proceedings whether at trial or by way of settlement, the parties shall
         negotiate in good faith for a reasonable share to Cantab of any sums
         recovered or awarded in respect of the infringement to compensate
         Cantab as well as Novavax for losses sustained by reason of the
         infringement, taking into account Cantab's interest relative to other
         interests in the Licensed IP and the nature of the infringement.

5.3      If Novavax decides not to enforce or defend the Licensed Patent Rights,
         it shall notify Cantab in writing and Cantab shall be entitled to do so
         at its own cost and expense upon


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April 22 1999                                          Novavax/Cantab - page: 11

         giving written notice to Novavax within 30 days of the date of Novavax'
         notice. Where Cantab does so, Novavax shall lend its name to any
         infringement proceedings and shall sign any documents that Cantab
         reasonably requests in relation to any such activity or proceedings and
         shall give Cantab all reasonable assistance requested by Cantab in
         relation to them (at no charge or expense to Cantab, other than with
         respect to reasonable out-of-pocket expenses, but Novavax shall not be
         bound to incur unreasonable expenses). If Cantab succeeds in any such
         proceedings whether at trial or by way of settlement, the parties shall
         negotiate in good faith for a reasonable share to Cantab of any sums
         recovered or awarded in respect of the infringement to compensate
         Cantab as well as Novavax for losses sustained by reason of the
         infringement, taking into account Cantab's interest relative to other
         interests in the Licensed IP and the nature of the infringement.

 5.4     If during the term of this Agreement either Party: (a) receives any
         notice, claim or proceedings from any third party alleging infringement
         of that third party's intellectual property as a result of either
         Party's activities or proposed activities in relation to this Agreement
         or use and exploitation of the Licensed Patent Rights; or (b) receives
         any information that could reasonably give rise to a potential claim or
         proceedings alleging such patent infringement, the Party receiving that
         notice shall:

 5.4.1   forthwith notify the other Party of such notice, claim or proceedings;
         and

 5.4.2   make no admission of liability.

         In the event of any such claim which alleges that the Licensed IP
         infringes such third party's patent or copyright, Novavax agrees to
         defend such claim and pay any settlement or judgment arising from such
         claim. Such obligation shall be subject to Novavax' receipt of prompt
         notice of such claim and its sole control of any such defence and/or
         the incurring of any expenses relating thereto. Such obligation shall
         not apply to any modification made to the Licensed IP, the method of
         practice of the Licensed IP by any person other than Novavax and/or the
         combination of any product provided by Novavax with any other product
         or technology.

 5.5     In the event of any such claim which alleges that the Licensed Product
         infringes such third party's intellectual property rights, Cantab
         agrees to defend such claim, pay any settlement or judgment arising
         from such claim and to indemnify and hold Novavax harmless from and
         against any and all liability, loss, damage or expense arising from
         such claim other than a claim arising solely from the Licensed IP or
         the Novasome Adjuvant. Such obligation shall be subject to Cantab's
         prompt notice of such claim and its sole control of any such defence
         and/or the incurring of any expenses relating thereto.

 6.      WARRANTIES

 6.1     Subject to the limitations set forth in Clause 11.2 hereto and to the
         disclosures set forth in Schedule 1 to this Agreement, Novavax warrants
         and undertakes as at the date of this Agreement that:-


<PAGE>   12
April 22 1999                                          Novavax/Cantab - page: 12

 6.1.1   to the best of its knowledge and belief, it is the sole owner with full
         title the Licensed IP and, to the best of its knowledge and belief, the
         use, exploitation or commercialisation of the Licensed IP under the
         terms of this Agreement will not infringe the rights of any third
         party, and Novavax has not received notice of any claim or threat of a
         claim by a third party alleging that the exploitation of the licensed
         IP would infringe such third party's intellectual property;

 6.1.2   it will use commercially reasonable efforts to apply for, pursue to
         grant, maintain and protect against infringement all Licensed Patent
         Rights except as permitted by this Agreement; and

 6.1.3   it will not, subject to Clause 10.5 of this Agreement, at any time
         during the term of this Agreement while Cantab is in compliance with
         its payment and confidentiality obligations hereunder, grant to any
         third party any right, title or licence to manufacture, use or exploit
         the Licensed IP within the Field in any manner whatsoever nor itself
         manufacture, use or exploit any Licensed Product, in the Field (except
         for the benefit of Cantab or except as permitted by this Agreement).

 6.2     Novavax will name a contact who shall be an authorized representative
         of Novavax to conduct Novavax's part in the contacts meetings and
         transfers of documentation and other arrangements with Cantab defined
         in clauses 7.1.6 and 7.1.7 below.

 7.      CANTAB'S OBLIGATIONS

 7.1     Cantab shall:-

 7.1.1   use all commercially reasonable endeavours to market, distribute,
         promote and sell the Licensed Product within the Field or procure the
         same through a sublicensee;

 7.1.2   only to appoint sub-licensees and distributors who have the requisite
         experience, staff and resources adequately to perform their obligations
         and who will use all reasonable efforts to market, distribute, promote
         and sell the Licensed Products;

 7.1.3   promptly notify Novavax of any infringement of the Licensed IP which
         may come to its attention;

 7.1.4   ensure that all Licensed Products sold and developed by it, its
         distributors or sub-licensees under this Agreement are of satisfactory
         quality and that the manufacture, distribution, promotion, marketing
         and sale of such product complies with all laws and regulations in
         operation in the jurisdiction in which they are supplied; and

 7.1.5   promptly notify Novavax of any product safety, regulatory or marketing
         information of which it becomes aware that has the potential adversely
         to affect sales of the Licensed Product;

 7.1.6   provide personnel including a named contact involved in the development
         of the Licensed Product for meetings with Novavax to review research
         and clinical testing results and developments, not less frequently than
         quarterly unless otherwise agreed between the named contact and the
         corresponding named contact from Novavax, which meetings each Party
         shall use commercially reasonable efforts to hold face-to-face (or if
         agreed impractical to hold face-to-face then by a conference call) at
         each Party's facility


<PAGE>   13
April 22 1999                                          Novavax/Cantab - page: 13

         on an alternating basis. Cantab and Novavax shall include in their
         periodical meetings and reviews under this agreement consideration and
         negotiation in good faith of appropriate performance obligations by
         Cantab concerning the achievement of milestones 3.2.2-3.2.4;

 7.1.7   provide, not less frequently than quarterly, any research reports,
         study records, or other material documents in its possession related to
         the Novavax Materials, by reliable overnight delivery service;

 7.1.8   at Cantab's own expense, comply with, and ensure that each sub-licensee
         and/or distributor complies with, all laws, regulations, rules,
         ordinances or directives relating to the manufacture, marketing, sale
         or distribution of Licensed Products, including any laws, regulations,
         rules, ordinances or directives relating to the export or import of
         Licensed Products to or from any country and/or relating to the recall
         of any Licensed Product.

 7.1.9   Cantab agrees to use its commercially reasonable endeavours to find and
         enter agreement with a suitable sublicensee, and to use its
         commercially reasonable endeavours to ensure that the studies necessary
         for the achievement of milestones 3.2.2 to 3.2.4 inclusive are carried
         out.

 8.      LIABILITY

 8.1     Cantab shall indemnify and hold harmless Novavax against all liability,
         damages or claims arising from the use of the Licensed IP by Cantab for
         research or clinical studies and subsequently by the exploitation of
         the Licensed Product save and to the extent where any such liability
         arises solely from the negligence or willful default of Novavax or
         otherwise by reason of any breach by Novavax of warranties given in
         this Agreement.

 8.2     Novavax shall indemnify and hold harmless Cantab against all liability,
         damages or claims arising from the use and exploitation of the Licensed
         IP authorized under the terms of this Agreement or the sale by Cantab
         (or any sublicense or distributor) of Licensed Product incorporating
         Novasomes Adjuvant manufactured by Novavax where such liability arises
         from the negligence or willful default of Novavax or otherwise by
         reason of any breach by Novavax of warranties given in this Licence
         Agreement.

 8.3     Neither party shall be liable to the other in contract, tort,
         negligence, breach of statutory duty or otherwise for any loss, damage,
         cost or expense of any nature incurred or suffered by that party of an
         indirect or consequential nature including any economic loss or other
         loss of turnover, profits, business or goodwill.

         Notwithstanding anything to the contrary in this Agreement, Novavax
         shall not be liable to Cantab for any amount in excess of the greater
         of the amount actually received by Novavax pursuant to this Agreement
         or US$1,000,000.


<PAGE>   14
April 22 1999                                          Novavax/Cantab - page: 14

 8.4     Each party acknowledges that it shall be solely responsible for the
         performance of its obligations under this Agreement on its premises
         including (without prejudice to the generality of the foregoing) the
         health and safety of its employees and all other regulatory, legal and
         other requirements (including without limitation all health and safety
         and environmental legislation and guidelines) relating to the
         performance of its obligations under this Agreement and that the other
         party shall be in no manner responsible for the same.

 9.      CONFIDENTIALITY AND SECURITY

 9.1     Each Party (the "Recipient Party") shall keep the Confidential
         Information of the other Party (the "Disclosing Party") secret and
         confidential and shall not without the prior consent of the other Party
         directly or indirectly disclose or permit the same to be disclosed to
         any third party for any reason or use the same save as expressly
         provided by this Agreement or the Option Agreement or the Materials
         Transfer Agreement.

 9.2     The obligations of confidence referred to in Clause 9.1 shall not
         extend to all or any part of such Confidential Information which:-

 9.2.1   is or becomes generally available to the public otherwise than by
         reason of breach by the Recipient Party of the provisions of this
         Agreement;

 9.2.2   the Recipient Party can show by documentary evidence was within its
         possession or control prior to the date upon which it was received from
         the disclosing party free from any obligation of confidentiality; or
         which the recipient party can show by documentary evidence came into
         its possession or control from a third party free from any obligation
         of confidentiality by such third party subsequent to the date of the
         Option Agreement; or

 9.2.3   is subsequently disclosed to the Recipient Party without obligations of
         confidence by a third party owing no such obligations to the Disclosing
         Party in respect of that Confidential Information.

         The Recipient Party may disclose Confidential Information to the extent
         such is required by law to be disclosed (including as part of any
         regulatory submission or approval process) and then only after prompt
         written notice of this requirement has been given to the Disclosing
         Party so that it may, if so advised, seek appropriate relief to prevent
         such disclosure provided always that in such circumstances such
         disclosure shall be only to the extent so required and shall be subject
         to prior consultation with the Disclosing Party with a view to agreeing
         timing and content of such disclosure.

 9.3     The obligations of the Parties under Clause 9.1 shall survive the
         expiration or termination of this Agreement for whatever reason for a
         period expiring at the earlier of


<PAGE>   15
April 22 1999                                          Novavax/Cantab - page: 15

         five years following such termination or expiration or ten years
         following disclosure of the Confidential Information.

 10.     TERMINATION

 10.1    Cantab shall have the right to terminate its rights and obligations
         under this Agreement in respect of any part (or the whole) of the
         Licensed IP on 120 days written notice. In the event of any partial
         termination the rights and obligations of Cantab shall cease in respect
         of any terminated part but shall continue thereafter in accordance with
         the terms of this Agreement in respect of any and all non-terminated
         parts of the Licensed IP.

 10.2    Cantab shall have the right to terminate this Agreement upon giving
         written notice of termination to Novavax in the event Novavax commits a
         material breach of this agreement which is not cured within 30 days of
         Novavax's receipt of written notice of breach from Cantab identifying
         the breach and requiring its remedy.

 10.3    Novavax shall have the right to terminate this Agreement upon giving
         written notice of termination to Cantab upon the occurrence of any of
         the following events at any time during this Agreement:-

 10.3.1  Cantab commits a breach of this Agreement relating to the payment of
         money actually due to Novavax which shall not have been cured within 5
         days of receipt by Cantab of written notice of breach from Novavax
         identifying the breach and requiring its remedy;

 10.3.2  Cantab commits any material breach of this Agreement, other than a
         breach specified in clause 10.3.1, which shall not have been remedied
         within 30 days of the receipt by Cantab of a written notice from
         Novavax identifying the breach and requiring its remedy; or

 10.3.3  if an Insolvency Event occurs in relation to Cantab.

 10.4    In the event of any termination hereunder, Cantab shall promptly return
         all Novavax Confidential Information to Novavax. The license granted
         hereunder shall cease immediately upon such termination and Cantab
         shall no longer have any right or interest to use any Licensed IP or to
         manufacture, sell, market, distribute or sublicense the Licensed
         Product; provided however, that Cantab (and/or its sublicensee) shall
         have the right to continue to sell Licensed Product which has already
         been manufactured, for a period of 30 days after the effective date of
         such termination, subject to the continued applicability of Clause 3 of
         this Agreement to any such sale and time period. In case of partial
         termination under clause 10.1, this subclause applies only to the
         terminated part. Termination of this Agreement, in whole or in part,
         shall be without prejudice to obligations and/or rights accrued prior
         to the effective date of such termination.
<PAGE>   16
April 22 1999                                          Novavax/Cantab - page: 16

 10.5    Novavax shall have the right, at its option, in the event Cantab
         breaches its obligations under Clause 3.4 of this Agreement to convert
         the license granted herein to a non-exclusive license, which shall
         result in the termination of Novavax' obligations under Clause 6.1.3 of
         this Agreement. Such right shall be in addition to any other right
         Novavax may have under this Agreement.

         Beginning in 2004, in the event that Cantab does not, directly or
         indirectly, commence sales and/or marketing of a Licensed Product in a
         country in which such sales and/or marketing are planned (a 'Planned
         Country'), within six months of the date such sales or marketing are
         planned in accordance with Cantab's (or its sublicensee's) marketing
         plan, as delivered to Novavax in accordance with Clause 7.1.7 of this
         Agreement, which failure to commence sales and/or marketing is not
         caused directly by the inability to obtain regulatory approval
         necessary to commence such sales and/or marketing after commercially
         reasonable efforts to obtain such approval ('regulatory approval
         failure'), the Parties hereto shall promptly commence and diligently
         pursue discussion regarding such event. Such discussions shall include
         whether commercialization of the Licensed Products is reasonable with
         respect to the Planned Country and whether the exclusivity set forth in
         Clauses 2.1 and 6.1.3 should continue to apply to the Planned Country.
         In the event that Cantab and Novavax do not agree to an alternative
         plan during the period of 24 months from the date of the planned sale
         and/or marketing in the Planned Country, Novavax shall have the right,
         upon 10 days written notice to Cantab at the expiration of such 24
         month period, if sales and/or marketing in the Planned Country have
         not yet commenced and if such failure is not caused directly by
         regulatory approval failure, to convert the license granted herein to a
         non exclusive license with respect to the Planned Country, which shall
         result in the termination of Novavax's obligations under Clause 6.1.3
         of this Agreement with respect to the Planned Country.

 11.     GENERAL

 11.1    This Agreement shall be deemed to have effect from the date hereof and
         shall supersede any other agreement whether written or oral with
         respect to the performance of their respective obligations by the
         parties provided that for the avoidance of doubt the Confidentiality
         Agreements and the Materials Transfer Agreement (save only as expressly
         amended by this Agreement) and clause 4 of Schedule 2 of the Option
         Agreement together with clauses 3.1, 5.1 and 8.2.1 of the Option
         Agreement shall remain in full force and effect in accordance with
         their terms.

 11.2    Each party acknowledges that in entering into this Agreement it does
         not do so on the basis of and does not rely on any representation,
         warranty or other provision save as expressly provided herein and all
         conditions, warranties and other terms implied by statute or common law
         are hereby excluded to the fullest extent permitted by law.

 11.3    Any notice given under this Agreement shall be sufficiently served if
         in writing and sent


<PAGE>   17
April 22 1999                                          Novavax/Cantab - page: 17

         by both facsimile transmission and air mail post or courier to the
         address and fax number of the recipient party set out below:

         NOVAVAX, INC.
         8320 Guilford Road, Suite C
         Columbia, MD 21046 USA
         Fax No.: (00)(1) 301-854-3901

         CANTAB PHARMACEUTICALS RESEARCH LIMITED
         310 Cambridge Science Park
         Milton Road, Cambridge CB4 OWG
         Fax No.: (01l)(44) 1223 423458

         Notice of any modification or amendment to the address or fax number of
         a party must itself be made in writing to the other party in accordance
         with the terms of this Clause.

 11.4    Neither party is authorised to act as the agent of the other for any
         purpose whatsoever and neither party shall on behalf of the other enter
         into, or make, or purport to enter into or make or represent that it
         has any authority to enter into or make any contract or any
         representation or warranty. Nothing in the Agreement shall be deemed to
         constitute a partnership between the other parties and neither of the
         parties shall do or suffer to be done anything whereby it may be
         represented as a partner of the other party.

 11.5    Each of the parties shall bear its own cost and expenses incidental to
         the preparation, negotiation and execution of this Agreement and the
         Supply Agreement.

 11.6    This Agreement is personal to Cantab and shall not be capable of
         assignment, sublicensing (subject and without prejudice to Section 2.2
         of this Agreement) or transfer by Cantab (whether in whole or in part)
         without the prior written consent of Novavax, which shall not be
         unreasonably withheld. Cantab shall have the right to assign or
         transfer this Agreement to an entity into which it is merged or which
         acquires all or substantially all of the assets of the business line
         using the Licensed IP or all or substantially all of Cantab's capital
         stock. Cantab shall give Novavax not less than 45 days advanced written
         notice of any such proposed merger or sale. Novavax agrees to notify
         Cantab in writing within 20 days of receipt of a notice of a proposed
         merger or sale from Cantab, whether the party with which Cantab
         proposes entering such merger or sale transaction is a competitor of
         Novavax, involved in the field of adjuvants, and whether Novavax
         objects to such assignment or transfer of this Agreement on the basis
         that such would result in confidential, proprietary or non-public
         information becoming known by a competitor. If Novavax so objects,
         Cantab shall notify Novavax within 10 days of receipt of Novavax's
         notice whether it intends to complete the sale or merger. In the event
         Cantab does not provide Novavax such notice or notifies Novavax that
         it intends to complete such merger or sale, Novavax may, upon 10 days
         notice to Cantab,


<PAGE>   18
April 22 1999                                          Novavax/Cantab - page: 18

         terminate this Agreement and the license granted hereby, such
         termination to take effect immediately before said sale or merger.

 11.7    Any agreement to amend, vary or modify the terms of this Agreement in
         any manner shall be valid only if the amended, variation or
         modification is effected in writing and signed by duly authorised
         representatives of each of the parties hereto.

 11.8    No delay by either party in enforcing any of the provisions of this
         Agreement shall be deemed a waiver of that party's right subsequently
         to enforce such provision.

 11.9    If any term or provision or any part thereof contained herein shall be
         declared or become unenforceable invalid or illegal in any respect
         under the law of any relevant jurisdiction: (i) such term or provision
         or part thereof shall be deemed to have been severed from the remaining
         terms of this Agreement and the terms and conditions hereof shall
         remain in full force and effect as if this Agreement had been executed
         without the offending provision appearing herein; and (ii) the parties
         shall endeavour to agree and amend which to the fullest extent possible
         will give lawful effect to their intentions as expressed in any term or
         provision severed under this Clause 11.9.

 11.10   Any controversy or claim of whatsoever nature arising out of or
         relating in any manner whatsoever to this Agreement or any breach of
         any terms of this Agreement shall be governed by and construed in all
         respects in accordance with the laws of England, except that claims or
         controversies arising out of or relating to Cantab's obligations of
         confidentiality and non-disclosure hereunder shall be governed by and
         construed in all respects in accordance with the laws of the State of
         Maryland, USA. At the request of either party, any claim, dispute or
         controversy arising out of or in connection with this Agreement or a
         breach thereof shall be settled by arbitration conducted in London in
         accordance with the commercial arbitration rules then in effect of the
         American Arbitration Association. The costs of arbitration shall be
         divided equally between the parties except that the arbitrator(s) shall
         have the authority to allocate the costs according to equitable
         principles upon the request by either party. The arbitrator(s) shall
         have the express authority to award equitable remedies at the request
         of either party.

[Schedule 1 follows next:]


<PAGE>   19
April 22 1999                                          Novavax/Cantab - page: 19

SCHEDULE 1
LICENSED PATENT RIGHTS

<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------
USA Patent                    Patent Title                             Date of          USA            EC
  Number                                                             Issuance in     Expiration     Expiration
                                                                         USA            Date           Date
---------------------------------------------------------------------------------------------------------------
<S>             <C>                                                  <C>            <C>             <C>
4,853,228       Method of Manufacturing Paucimellar Lipid            8/1/89          7/28/07
                Vesicles

---------------------------------------------------------------------------------------------------------------
4,855,090       Method of Producing High Aqueous Volume              8/8/69          3/13/07
                Multilamellar Vesicles

---------------------------------------------------------------------------------------------------------------
4,895,452       Method and Apparatus for Producing Lipid             1/23/90         3/3/08
                Vesicles

---------------------------------------------------------------------------------------------------------------
4,911,928       Paucilamellar Lipid Vesicles                         3/27/90         3/7/07

---------------------------------------------------------------------------------------------------------------
4,917,951       Lipid Vesicles Formed of Surfactants and             4/17/90         11/24/07
                Steroids

---------------------------------------------------------------------------------------------------------------
5,000,960       Protein Coupling Lipid Vesicles                      3/19/91         1/19/09

---------------------------------------------------------------------------------------------------------------
5,013,497       Method and Apparatus for Producing Lipid             5/7/91
                Vesicles

---------------------------------------------------------------------------------------------------------------
5,032,457       Paucilamellar Lipid Vesicles Using Charge-           8/16/91         7/16/06
                localised, single chain, non-phospholipid
                Surfaciants

---------------------------------------------------------------------------------------------------------------
5,104,736       Reinforced paucilamellar Lipid Vesicles              4/14/92         6/26/09

---------------------------------------------------------------------------------------------------------------
4,147,723       Paucilamellar Lipid Vesicles                         9/15/92         6/8/06

---------------------------------------------------------------------------------------------------------------
5,234,767       Hybrid Paucilamellar Lipid Vesicles                  8/10/93         3/27/07

---------------------------------------------------------------------------------------------------------------
5,256,422       Lipid Vesicles Containing Water-in-Oil               10/23/93        3/28/11
                Emulsions

---------------------------------------------------------------------------------------------------------------
5,474,848       Paucilamellar Lipid Vesicles                         12/12/95        3/13/07        3/8/08

---------------------------------------------------------------------------------------------------------------
5,561,062       Method of Inhibiting viral Reproduction Using        10/1/96         10/1/93
                non-phospholipid Paucilamellar Liposomes

---------------------------------------------------------------------------------------------------------------
,*NVR-          Vaccines Containing Paucilamellar Lipid              *CIP
213CP           Vesicles as Immunological Adjuvants

---------------------------------------------------------------------------------------------------------------
</TABLE>


OTHER LICENSED PATENT AND APPLICATIONS INCLUDE:
European Patents and Applications:      PCT Applications:
0 349 583                               WO 88/06881
0 349 579                               WO 88/06882
0 352 282                               WO 88/06883
0 406 273                               WO 89/07929
0 746 338                               WO 95/22989
                                        WO 91/04013


Disclosure: L'Oreal opposed European Patent No 0 352 282 of Micro-Pak, Inc. Such
opposition was denied. L'Oreal has appealed such denial.

DISCLOSURE: NOVAVAX HAS LEARNED OF THE FOLLOWING PATENTS AND/OR APPLICATIONS,
WHICH INCLUDE CLAIMS WHICH MAY BE ARGUED TO BE EMCOMPASSED BY THE LICENSED IP:
US PATENT NO. 5,579,353 (WITH WO3/19781) AND W095/109751. NOVAVAX BELIEVES THAT
TO THE EXTENT THAT ANY SUCH CLAIMS WOULD BE INFRINGED BY THE LICENSED
PRODUCTS, SUCH CLAIMS MAY NOT BE VALID


<PAGE>   20
April 22 1999                                          Novavax/Cantab - page: 20

   ==========================================================================

IN WITNESS WHEREOF the Parties have caused this Licence Agreement to be
executed:

         for and on behalf of Novavax, Inc.: [date] 29 April 1999
         [signature]     /s/ Mitchell J. Kelly
                        --------------------------------------------

         [name and official position of signatory]
          Mitchell J. Kelly             President & CEO
         -----------------------------------------------------------


         for and on behalf of Cantab Pharmaceuticals Research Limited
         [date] 22 April 1999
         [signature]     /s/ Jurek S. Sikorski
                        --------------------------------------------

         [name and official position of signatory]
          Jurek S. Sikorski         CHIEF EXECUTIVE OFFICER
         -----------------------------------------------------------

         This Agreement is endorsed in accordance with its terms with an
         execution for and on behalf of Novavax Inc.'s subsidiaries Micro-Pak,
         Inc. and Micro Vesicular Systems, Inc., who agree to be bound hereby to
         the extent within written:-

         for and on behalf of Micro-Pak, Inc. [date] 29 April 1999
         [signature]     /s/ Mitchell J. Kelly
                        --------------------------------------------

         [name and official position of signatory]
          Mitchell J. Kelly             President
         -----------------------------------------------------------

         for and on behalf of Micro Vesicular Systems, Inc. [date] 29 April 1999
         [signature]      /s/ Mitchell J. Kelly
                        --------------------------------------------

         [name and official position of signatory]
          Mitchell J. Kelly             President
         -----------------------------------------------------------