EXHIBIT 10.46
                                  -------------

                          PLEDGE AND SECURITY AGREEMENT
                          -----------------------------

      THIS PLEDGE AND SECURITY AGREEMENT, dated as of February ___, 2000, by and
between GENETIC VECTORS,  INC., a Florida corporation  ("Pledgor"),  and ORBITER
FUND, LTD. (the "Pledgee").

      WHEREAS,  Pledgee is the holder of a Promissory  Note (the "Note") of even
date herewith made by Pledgor in the original principal amount of $250,000;

      WHEREAS, Pledgee desires to obtain a security interest in certain property
owned by Pledgor;

      WHEREAS,  Pledgee  acknowledges  that Pledgor has  previously  pledged and
granted security interests in the Pledged Collateral as defined herein; and

      WHEREAS,  as an  inducement to Pledgee's  making of the Note,  Pledgor has
agreed to grant to Pledgee a security interest in and to the Pledged  Collateral
(as hereinafter defined).

      NOW, THEREFORE,  in consideration of the premises and the mutual covenants
herein contained,  and for other good and valuable  consideration,  the adequacy
and receipt of which are hereby acknowledged, the parties hereto hereby agree as
follows:

                                   ARTICLE 1.

                         DEFINITIONS AND INTERPRETATIONS
                         -------------------------------

      Section 1.1.  Interpretations.
                    ---------------

      Nothing  herein  expressed or implied is intended or shall be construed to
confer upon any person other than Pledgee any right, remedy or claim under or by
reason hereof.



<PAGE>

      Section 1.2.  Obligations Secured.
                    -------------------

      The  obligations  secured hereby are the obligations of Pledgor to Pledgee
under the Note issued by Pledgor to Pledgee,  in the  maximum  principal  amount
thereof  outstanding from time to time, and any additional amounts payable by or
chargeable to Pledgor thereunder or hereunder (collectively, the "Obligations").

                                   ARTICLE 2.

                 PLEDGE AND ADMINISTRATION OF PLEDGED COLLATERAL
                 -----------------------------------------------

      Section 2.1.  Pledged Collateral.
                    ------------------

          (a)  Pledgor hereby pledges to Pledgee, and creates in Pledgee for its
benefit,  subject  to the  rights of  previous  pledgees  and other  holders  of
security  interests in the Pledged  Collateral (as defined  herein),  a security
interest,  for such time as the Obligations shall remain outstanding,  in and to
all of Pledgor's right, title and interest in and to:

               (i)  the  property (the "PLEDGED  PROPERTY")  listed on EXHIBIT 1
attached hereto, including, without limitation, any securities described therein
(which securities are collectively referred to as the "PLEDGED SECURITIES"), now
owned  by  Pledgor,  and  all  machinery,   equipment,   automobiles,   accounts
receivable,  inventory and general  intangibles,  patents,  patent applications,
licenses  and all other  intellectual  property  rights  owned by or acquired by
Pledgor on or after the date of this Agreement; and

               (ii) all  products and proceeds  from the Pledged  Property.  The
Pledged Property in Section  2.1(a)(i)  hereof,  the Pledged  Securities and the
products thereof and the proceeds of all such items are hereinafter collectively
referred  to as the  "PLEDGED  COLLATERAL."  The  security  interest  granted by
Pledgor to Pledgee in and to the Pledged  Collateral is subject to the rights of

                                       2
<PAGE>

previous  pledgees  and other  holders  of  security  interests  in the  Pledged
Collateral.

          (b) Simultaneously  with the execution and delivery of this Agreement,
Pledgor shall make,  execute,  acknowledge,  file, record and deliver to Pledgee
any documents  reasonably  requested by Pledgee to perfect its security interest
in the Pledged  Collateral.  The Pledgee shall be responsible for filing any and
all  documents  required  to  perfect  its  security  interest  in  the  Pledged
Collateral.  Simultaneously  with the execution and delivery of this  Agreement,
Pledgor shall make,  execute,  acknowledge and deliver to Pledgee such documents
and  instruments,   including,   without   limitation,   financing   statements,
certificates,  affidavits and forms as may, in Pledgee's reasonable judgment, be
necessary to effectuate,  complete or perfect, or to continue and preserve,  the
security interest of Pledgee in the Pledged  Collateral,  and Pledgee shall hold
such  documents  and  instruments  as  secured  party,  subject to the terms and
conditions contained herein.

      Section 2.2.  Rights; Interests; Etc.
                    -----------------------

          (a) So long as no Event of Default (as hereinafter defined) shall have
occurred and be continuing:

               (i) Pledgor  shall  be  entitled to  exercise any  and all rights
pertaining  to the Pledged  Collateral  or any part  thereof for any purpose not
inconsistent with the terms hereof; and

               (ii)  Pledgor  shall be  entitled to  receive and  retain any and
all payments paid or made in respect of the Pledged Collateral.

          (b) Upon  the  occurrence and  during the  continuance of  an Event in
Default:


                                       3
<PAGE>

               i. Subject to the rights of previous  pledgees and other  holders
of  security  interests  in  the  Pledged  Collateral  and  subject  to  Section
2.2(b)(iii)  hereof, all rights of Pledgor to exercise the rights which it would
otherwise be entitled to exercise  pursuant to Section  2.2(a)(i)  hereof and to
receive  payments  which it would  otherwise be authorized to receive and retain
pursuant to Section  2.2(a)(ii)  hereof shall be suspended,  and all such rights
shall thereupon become vested in Pledgee who shall thereupon have the sole right
to  exercise  such  rights and to receive  and hold as Pledged  Collateral  such
payments;  PROVIDED,  HOWEVER,  that if Pledgee shall become  entitled and shall
elect to  exercise  its right to realize on the Pledged  Collateral  pursuant to
Article V hereof, then all cash sums received by Pledgee, or held by Pledgor for
the benefit of Pledgee  and paid over  pursuant  to Section  2.2(b)(ii)  hereof,
shall be applied against any outstanding Obligations.

               (ii) Subject to the rights of previous pledgees and other holders
of security interests in the Pledged Collateral, all interest, dividends, income
and other payments and  distributions  which are received by Pledgor contrary to
the  provisions of Section  2.3(b)(i)  hereof shall be received in trust for the
benefit of Pledgee, shall be segregated from other property of Pledgor and shall
be forthwith paid over to Pledgee;

               (iii) notwithstanding  anything contained hereto to the contrary,
Pledgor  shall  retain any voting  rights it may have with respect to any of the
Pledged Securities until such time as Pledgee is entitled and elects to exercise
its rights to realize on the Pledged Securities pursuant to Article V hereof.

          (c) Each  of the  following  events shall  constitute a  default under
this Agreement (each an "EVENT OF DEFAULT"):


                                       4
<PAGE>


               (i) any default,  whether in whole or in part, shall occur in the
payment  to  Pledgee  of  principal,  interest  or  other  item  comprising  the
Obligations as and when due, which default shall continue for a period of thirty
(30) days after the receipt of written notice thereof by Pledgor;

               (ii) any default, whether in whole or in part, shall occur in the
due  observance or performance  of any other  covenant,  term or provision to be
performed under this Agreement by Pledgor, or the Note, and all exhibits thereto
which default is not described in any other subsection of this Section, and such
default  shall  continue  for a period of thirty  (30) days after the receipt of
written notice thereof by Pledgor; PROVIDED, HOWEVER, that if Pledgor shall have
commenced  to cure such  default  within  such  thirty (30) day period and shall
proceed  continuously in good faith and with due diligence to cure such default,
then such period instead shall be sixty (60) days;

               (iii)  Pledgor  shall:  (1)  make a  general  assignment  for the
benefit  of its  creditors;  (2) apply for or consent  to the  appointment  of a
receiver,  trustee,  assignee,  custodian,  sequestrator,  liquidator or similar
official  for  itself  or any of its  assets  and  properties;  (3)  commence  a
voluntary case for relief as a debtor under the United States  Bankruptcy  Code;
(4) file with or otherwise  submit to any  governmental  authority any petition,
answer or other document seeking:  (A)  reorganization,  (B) an arrangement with
creditors or (C) to take advantage of any other present or future applicable law
respecting bankruptcy, reorganization, insolvency, readjustment of debts, relief
of debtors,  dissolution or liquidation; (5) file or otherwise submit any answer
or other document admitting or failing to contest the material  allegations of a
petition  or other  document  filed or  otherwise  submitted  against  it in any


                                       5
<PAGE>

proceeding  under any such  applicable  law, or (6) be adjudicated a bankrupt or
insolvent by a court of competent jurisdiction; or

               (iv) any case,  proceeding  or other  action  shall be  commenced
against  Pledgor for the purpose of effecting,  or an order,  judgment or decree
shall be entered by any court of competent  jurisdiction  approving (in whole or
in part)  anything  specified in Section  2.2(c)(iii)  hereof,  or any receiver,
trustee, assignee, custodian,  sequestrator,  liquidator or other official shall
be  appointed  with  respect to Pledgor,  or shall be appointed to take or shall
otherwise  acquire  possession  or control of all or a  substantial  part of the
assets and  properties  of  Pledgor,  and any of the  foregoing  shall  continue
unstayed and in effect for any period of ninety (90) days.

                                    ARTICLE 3

                          ATTORNEY-IN-FACT; PERFORMANCE
                          -----------------------------

      Section 3.1.  Pledgee Appointed Attorney-In-Fact.
                    ----------------------------------

      Upon the  occurrence of an Event of Default and only as long as such Event
of Default shall be continuing,  and subject to the rights of previous  pledgees
and other  holders of  security  interests  in the Pledged  Collateral,  Pledgor
hereby appoints  Pledgee as Pledgor's  attorney-in-fact,  with full authority in
the place and stead of Pledgor  and in the name of Pledgor  or  otherwise,  from
time to time in  Pledgee's  discretion  to take any action  and to  execute  any
instrument  which  Pledgee may  reasonably  deem  necessary  to  accomplish  the
purposes  of this  Agreement,  including,  without  limitation,  to receive  and
collect all  instruments  made payable to Pledgor  representing  any payments in
respect of the Pledged Collateral or any part thereof and to give full discharge
for the same.  Pledgee may demand,  collect,  receipt for,  settle,  compromise,
adjust,  sue for,  foreclose,  or realize on the Pledged  Collateral as and when
Pledgee may determine.  To facilitate  collection,  and subject to the rights of


                                       6
<PAGE>

previous  pledgees  and other  holders  of  security  interests  in the  Pledged
Collateral,  Pledgee  may notify  account  debtors  and  obligors on any Pledged
Collateral to make payments directly to Pledgee.

      Section 3.2.  Pledgee May Perform.
                    -------------------

      If Pledgor fails to perform any agreement  contained herein,  Pledgee,  at
its option, may itself perform, or cause performance of, such agreement, and the
reasonable expenses of Pledgee incurred in connection therewith shall be payable
by Pledgor under Section 8.3.

                                   ARTICLE 4.

                         REPRESENTATIONS AND WARRANTIES
                         ------------------------------

      Section 4.1.  Authorization; Enforceability.
                    -----------------------------

      Each of the parties  hereto  represents and warrants that it has taken all
action  necessary to authorize the execution,  delivery and  performance of this
Agreement  and the  transactions  contemplated  hereby;  and upon  execution and
delivery,  this Agreement shall constitute a valid and binding obligation of the
respective party, subject to applicable bankruptcy, insolvency,  reorganization,
moratorium  and similar laws  affecting  creditors'  rights or by the principles
governing the availability of equitable remedies.

      Section 4.2.  Ownership of Pledged Collateral.
                    -------------------------------

      Pledgor  warrants and represents  that Pledgor is the legal and beneficial
owner of the Pledged Collateral.

      Section 4.3.  Due Organization.
                    ----------------

      Pledgor  warrants  and  represents  that  it:  (i) is a  corporation  duly
organized,  validly existing and in good standing under the laws of the State of
Florida;  (ii) has the corporate power and authority  necessary to entitle it to
use its corporate  name and to own,  lease or otherwise  hold its properties and


                                       7
<PAGE>

assets and to carry on its  business as  presently  conducted  or proposed to be
conducted;  and (iii) is duly  qualified  and in good standing to do business as
presently conducted or proposed to be conducted.

                                   ARTICLE 5.

                    DEFAULT; REMEDIES; SUBSTITUTE COLLATERAL
                    ----------------------------------------

      Section 5.1.  Default and Remedies.
                    --------------------

            (a) If an Event of Default  described in Section  2.2(c)(i) and (ii)
occurs and is  continuing  for the period set forth  therein,  then in each such
case Pledgee may declare the principal amount to be due and payable immediately,
by a notice in writing to Pledgor, and upon any such declaration, such principal
amount  shall  become  immediately  due and  payable.  If an  Event  of  Default
described  in  Sections  2.2(c)(iii)  or (iv) occurs and is  continuing  for the
period  set  forth  therein,  then  the  principal  amount  of  the  Note  shall
automatically  become  immediately due and payable without  declaration or other
act on the part of Pledgee.

            (b) Upon  the  occurrence  of an Event of  Default,  Pledgee  shall,
subject  to the  rights of  previous  pledgees  and other  holders  of  security
interests   in  the  Pledged   Collateral,   (i)  be  entitled  to  receive  all
distributions with respect to the Pledged Collateral,  (ii) to cause the Pledged
Collateral to be transferred  into the name of Pledgee or its nominee,  (iii) to
dispose of the Pledged  Collateral,  and (iv) to realize upon any and all rights
in the Pledged Collateral then held by Pledgee.

      Section 5.2.  Method of Realizing Upon the Pledged Collateral:
                    Other Remedies.
                    --------------

      Upon the occurrence of an Event of Default,  in addition to any rights and
remedies  available  at law or in equity,  and subject to the rights of previous
pledgees and other holders of security interests in the Pledged Collateral,  the


                                       8
<PAGE>

following  provisions  shall govern  Pledgee's right to realize upon the Pledged
Collateral;

          (a) Any item of the Pledged  Collateral  may be sold for cash or other
value in any number of lots at brokers board, public auction or private sale and
may be sold without demand,  advertisement  or notice (except that Pledgee shall
give Pledgor  thirty (30) business  days' prior  written  notice of the time and
place  or of the  time  after  which  a  private  sale  may be made  (the  "Sale
Notice")),  which notice shall in any event be commercially  reasonable.  At any
sale or sales of the Pledged  Collateral,  Pledgor may bid for and  purchase the
whole or any part of the Pledged  Collateral and, upon compliance with the terms
of such  sale,  may  hold,  exploit  and  dispose  of the same  without  further
accountability  to Pledgee.  Pledgor will  execute and  deliver,  or cause to be
executed and  delivered,  such  instruments,  documents,  assignments,  waivers,
certificates,  and  affidavits  and supply or cause to be supplied  such further
information and take such further action as Pledgee  reasonably shall require in
connection with any such sale.

          (b) Subject to the rights of previous  pledgees  and other  holders of
security interests in the Pledged Collateral,  any cash being held by Pledgee as
Pledged Collateral and all cash proceeds received by Pledgee in respect of, sale
of,  collection  from, or other  realization upon all or any part of the Pledged
Collateral shall be applied as follows:

                (i) to the payment of all  amounts due Pledgee for the  expenses
reimbursable  to it or them  hereunder  or owed to it  pursuant  to Section  8.3
hereof;

                (ii) to the  payment  of the  amounts  then due and  unpaid  for
principal of and interest on the Note.

                (iii) the  balance,  if any,  to the person or persons  entitled
thereto, including, without limitation, Pledgor.


                                       9
<PAGE>


          (c) Subject to the rights of previous  pledgees  and other  holders of
security interests in the Pledged  Collateral,  in addition to all of the rights
and  remedies  which  Pledgor and Pledgee may have  pursuant to this  Agreement,
Pledgor and Pledgee  shall have all of the rights and remedies  provided by law,
including, without limitation, those under the Uniform Commercial Code.

          (d)

                (i) Subject to the rights of previous pledgees and other
holders of security interests in the Pledged Collateral, if Pledgor fails to pay
such amounts due upon the occurrence of an Event of Default which is continuing,
then Pledgee may institute a judicial  proceeding for the collection of the sums
so due and unpaid, may prosecute such proceeding to judgment or final decree and
may enforce the same against  Pledgor and collect the monies adjudged or decreed
to be payable in the manner  provided  by law out of the  property  of  Pledgor,
wherever situated.

                (ii) Pledgor  agrees that it shall be liable for any  reasonable
expenses  incurred by Pledgee in connection  with  enforcement,  collection  and
preservation of the Note, including,  without limitation,  reasonable legal fees
and  expenses,  and such  amounts  shall be deemed  included  under  Section 8.3
hereof.

      Section 5.3.  Proofs of Claim.
                    ---------------

          In case of the pendency of any receivership,  insolvency, liquidation,
bankruptcy,  reorganization,   arrangement,  adjustment,  composition  or  other
judicial  proceeding  relating to Pledgor or the  property of Pledgor or of such
other obligor or their creditors, Pledgee (irrespective of whether the principal
of the Note shall then be due and payable as therein expressed or by declaration
or otherwise and  irrespective  of whether Pledgee shall have made any demand on


                                       10
<PAGE>

Pledgor  for the  payment of overdue  principal,  if any,  or  interest)  shall,
subject  to the  rights of  previous  pledgees  and other  holders  of  security
interests in the Pledged Collateral,  be entitled and empowered, by intervention
in such proceeding or otherwise:

                (i) to file and prove a claim for the whole  amount of principal
of the Note and  interest  owing and  unpaid in  respect of the Note and to file
such other papers or documents as may be necessary or advisable in order to have
the claims of Pledgee  (including  any claim for the  reasonable  legal fees and
expenses and other expenses paid or incurred by Pledgee permitted  hereunder and
of Pledgee allowed in such judicial proceeding), and

                (ii)  Subject  to the  rights  of  previous  pledgees  and other
holders of security interests in the Pledged Collateral,  to collect and receive
any monies or other  property  payable or  deliverable on any such claims and to
distribute the same; and any custodian, receiver, assignee, trustee, liquidator,
sequestrator or other similar official in any such judicial proceeding is hereby
authorized  by Pledgee to make such  payments to Pledgee  and, in the event that
Pledgee shall consent to the making of such payments directed to Pledgee, to pay
to Pledgee any amounts for expenses due it hereunder.

      Section 5.4.  Duties Regarding Pledged Collateral.
                    -----------------------------------

      Pledgee  shall  have no duty as to the  collection  or  protection  of the
Pledged Collateral or any income thereon or as to the preservation of any rights
pertaining  thereto,  beyond the safe custody and reasonable  care of any of the
Pledged Collateral actually in Pledgee's possession.


                                       11
<PAGE>

                                    ARTICLE 6

                              AFFIRMATIVE COVENANTS
                              ---------------------

      Pledgor  covenants  and agrees  that,  from the date  hereof and until the
Obligations  have been fully paid and  satisfied,  unless  Pledgee shall consent
otherwise in writing (as provided in Section 8.4 hereof):

      Section 6.1.  Existence, Properties, Etc.
                    ---------------------------

          (a) Pledgor shall do, or cause to be done, all things, or proceed with
due  diligence  with any  actions or courses of action,  that may be  reasonably
necessary  (i) to  maintain  its due  organization,  valid  existence  and  good
standing under the laws of its state of incorporation,  and (ii) to preserve and
keep in full force and effect all qualifications,  licenses and registrations in
those  jurisdictions in which the failure to do so could have a Material Adverse
Effect (as defined in this  Section  6.1(a));  and (b) Pledgor  shall not do, or
cause to be done,  any act  impairing  its  corporate  power or authority (i) to
carry on its  business  as now  conducted,  and (ii) to execute or deliver  this
Agreement or any other document  delivered in connection  herewith  (which other
loan instruments collectively shall be referred to as the "Loan Instruments") to
which it is or will be a party, or perform any of its  obligations  hereunder or
thereunder.  For purpose of this Agreement,  the term "Material  Adverse Effect"
shall mean any  material  and adverse  affect,  whether  individually  or in the
aggregate,  upon (a)  Pledgor's  assets,  business,  operations,  properties  or
condition, financial or otherwise; (b) the ability of Pledgor to make payment as
and  when  due of all  or any  part  of  the  Obligations;  or (c)  the  Pledged
Collateral.


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<PAGE>

      Section 6.2.  Accounts and Reports.
                    --------------------

      Pledgor shall maintain a standard  system of accounting in accordance with
generally accepted accounting  principles  consistently  applied and provide, at
its sole expense, to Pledgee the following:

          (a) as soon as available,  a copy of any notice or other communication
alleging any nonpayment or other material breach or default,  or any foreclosure
or other action  respecting any material  portion of its assets and  properties,
received  respecting  any of the  indebtedness  of  Pledgor in excess of $15,000
(other than the  Obligations),  or any demand or other request for payment under
any guaranty, assumption, purchase agreement or similar agreement or arrangement
respecting  the  indebtedness  or  obligations  of others in excess of  $15,000,
including  any  received  from  any  person  acting  on  behalf  of  Pledgee  or
beneficiary thereof; and

          (b) within  fifteen  (15)  business  days  after  the  making  of each
submission  or  filing,  a copy of any  report,  registration  statement,  proxy
statement,  financial statement,  notice or other document,  whether periodic or
otherwise, submitted to the shareholders of Pledgor, or submitted to or filed by
Pledgor  with  any  governmental   authority  involving  or  affecting  (i)  any
registration  of  Pledgor  or its  securities;  (ii)  Pledgor  that could have a
Material  Adverse Effect;  (iii) the  Obligations;  (iv) any part of the Pledged
Collateral or (v) any of the transactions  contemplated in this Agreement or the
Loan  Instruments,  including,  without  limitation,  those  submitted  or filed
pursuant to the Securities Act of 1933, as amended,  and the Securities Exchange
Act of 1934, as amended.



                                       13
<PAGE>

      Section 6.3.  Maintenance and Insurance.
                    -------------------------

          (a)  Pledgor  shall  maintain  or cause to be  maintained,  at its own
expense,  all of its assets and  properties in good working order and condition,
making all necessary repairs thereto and renewals and replacements thereof.

          (b)  Pledgor  shall  maintain  or cause to be  maintained,  at its own
expense, insurance in form, substance and amounts (including deductibles), which
Pledgor deems reasonably necessary to Pledgor's business, (i) adequate to insure
all assets and  properties  of Pledgor,  which  assets and  properties  are of a
character  usually  insured by persons  engaged in the same or similar  business
against  loss or  damage  resulting  from  fire or other  risks  included  in an
extended  coverage  policy;  (ii) against public liability and other tort claims
that  may  be  incurred  by  Pledgor;  (iii)  as  may be  required  by the  Loan
Instruments  or  applicable  law and  (iv)  as may be  reasonably  requested  by
Pledgee, all with adequate, financially sound and reputable insurers.

      Section 6.4.  Contracts and Other Collateral.
                    ------------------------------

      Pledgor shall perform all of its obligations under or with respect to each
instrument,  receivable,  contract and other intangible  included in the Pledged
Collateral to which Pledgor is now or hereafter  will be party on a timely basis
and  in  the  manner  therein  required,  including,  without  limitation,  this
Agreement.

      Section 6.5.  Defense of Collateral, Etc.
                    --------------------------

      Pledgor  shall defend and enforce its right,  title and interest in and to
any part of: (a) the  Pledged  Collateral;  and (b) if not  included  within the
Pledged Collateral, those assets and properties whose loss could have a Material
Adverse Effect,  Pledgor shall,  subject to the rights of previous  pledgees and
other holders of security interests in the Pledged Collateral,  defend Pledgee's
right,  title  and  interest  in and to  each  and  every  part  of the  Pledged
Collateral,  each  against all manner of claims and demands on a timely basis to


                                       14
<PAGE>

the full extent permitted by applicable law.

      Section 6.6.  Payment of Debts, Taxes, Etc.
                    -----------------------------

      Pledgor shall pay, or cause to be paid, all of its  indebtedness and other
liabilities  and perform,  or cause to be performed,  all of its  obligations in
accordance with the respective terms thereof, and pay and discharge, or cause to
be paid or discharged, all taxes, assessments and other governmental charges and
levies  imposed upon it, upon any of its assets and  properties on or before the
last day on which the same may be paid without penalty, as well as pay all other
lawful claims (whether for services, labor, materials, supplies or otherwise) as
and when due; PROVIDED,  HOWEVER,  that it shall not constitute a breach of this
paragraph  if Pledgor  fails to perform any such  obligation  or to pay any such
indebtedness or other liability (except for the Obligations),  tax,  assessment,
or governmental or other charge, levy or claim (i) if the effect of such failure
to pay or perform will not (A) accelerate the maturity thereof,  or of any other
debt or  obligation  of  Pledgor,  or (B)  subject  any part of the  assets  and
properties of Pledgor to sale or forfeiture.

                                   ARTICLE 7.

                               NEGATIVE COVENANTS
                               ------------------

      Pledgor  covenants  and  agrees  that,  from the  date  hereof  until  the
Obligations  have been  fully paid and  satisfied,  Pledgor  shall  not,  unless
Pledgee shall consent otherwise in writing:

      Section 7.1.  Liens and Encumbrances.
                    ----------------------

          incur any liens  incurred  in respect of  indebtedness  on the Pledged
Collateral which are superior to the Obligations.


                                       15
<PAGE>


                                   ARTICLE 8.

                                  MISCELLANEOUS
                                  -------------

      Section 8.1.  Notices.
                    -------

      All  notices or other  communications  required or  permitted  to be given
pursuant to this  Agreement  shall be in writing and shall be considered as duly
given on:  (a) the date of  delivery,  if  delivered  in person,  by  nationally
recognized  overnight  delivery  service or (b) five (5) days  after  mailing if
mailed from within the  continental  United  States by  certified  mail,  return
receipt  requested  to the party  entitled to receive  the same,  if to Pledgor,
Genetic Vectors,  Inc., 5201 N.W. 77th Avenue,  Suite 100, Miami, Florida 33166,
Attention:  Mead  M.  McCabe,  Jr.,  with a copy to  Clayton  E.  Parker,  Esq.,
Kirkpatrick  & Lockhart  LLP,  201 S.  Biscayne  Boulevard,  20th Floor,  Miami,
Florida 33131 and if to Pledgee, at the addresses shown on the books of Pledgor.
Any party may change its address by giving notice to the other party stating its
new address. Commencing on the tenth (10th) day after the giving of such notice,
such newly  designated  address shall be such party's address for the purpose of
all notices or other  communications  required or permitted to be given pursuant
to this Agreement.

      Section 8.2.  Severability.
                    ------------

      If any provision of this Agreement shall be held invalid or unenforceable,
such  invalidity  or  unenforceability  shall attach only to such  provision and
shall not in any  manner  affect or render  invalid or  unenforceable  any other
severable  provision of this Agreement,  and this Agreement shall be carried out
as if any such invalid or unenforceable provision were not contained herein.


                                       16
<PAGE>

      Section 8.3.  Expenses.
                    --------

      In the  event of an Event of  Default,  Pledgor  will pay to  Pledgee  the
amount of any and all reasonable  expenses,  including the  reasonable  fees and
expenses of its  counsel,  which  Pledgee or the Holder may incur in  connection
with: (i) the custody or preservation of, or the sale, collection from, or other
realization  upon,  any  of  the  Pledged  Collateral;   (ii)  the  exercise  or
enforcement  of any of the rights of Pledgee  hereunder  or (iii) the failure by
Pledgor to perform or observe any of the provisions hereof.

      Section 8.4.  Waivers, Amendments, Etc.
                    -------------------------

      Pledgee's  delay or  failure  at any time or times  hereafter  to  require
strict performance by Pledgor of any undertakings, agreements or covenants shall
not waiver,  affect,  or diminish any right of Pledgee  under this  Agreement to
demand strict compliance and performance herewith.  Any waiver by Pledgee of any
Event of Default  shall not waive or affect any other Event of Default,  whether
such Event of Default is prior or subsequent  thereto and whether of the same or
a different type. None of the undertakings,  agreements and covenants of Pledgor
contained in this  Agreement,  and no Event of Default,  shall be deemed to have
been waived by Pledgee, nor may this Agreement be amended,  changed or modified,
unless  such  waiver,  amendment,  change or  modification  is  evidenced  by an
instrument in writing specifying such waiver, amendment,  change or modification
and signed by the Holder.

      Section 8.5.  Continuing Security Interest.
                    ----------------------------

      This Agreement shall create a continuing  security interest in the Pledged
Collateral and shall:  (i) remain in full force and effect until payment in full
of the  Obligations;  and (ii) be binding  upon Pledgor and its  successors  and
(iii) inure to the benefit of Pledgee and its successors and permitted  assigns.
Upon the payment or  satisfaction in full of the  Obligations,  Pledgor shall be


                                       17
<PAGE>

entitled to the return,  at its expense,  of such of the Pledged  Collateral  as
shall not have been sold in  accordance  with  Section  5.2 hereof or  otherwise
applied pursuant to the terms hereof.

      Section 8.6.  Applicable Law: Jurisdiction.
                    ----------------------------

      This Agreement and the rights of the parties  hereunder  shall be governed
by and  construed in accordance  with the laws of the State of Florida,  without
regard to its conflicts of law principles. Pledgee and Pledgor hereto: (i) agree
that any legal  suit,  action or  proceeding  arising out of or relating to this
Agreement  shall be  instituted  only in a federal or state court in  Miami-Dade
County,  Florida;  (ii) waive any objection which they may now or hereafter have
to the laying of the venue of any such  suit,  action or  proceeding;  and (iii)
irrevocably  submit  to the  jurisdiction  of any  federal  or  state  court  in
Miami-Dade County, Florida, in any such suit, action or proceeding.  Pledgee and
Pledgor  hereto  agree that the  mailing of any  process in any suit,  action or
proceeding in accordance  with the notice  provisions  of this  Agreement  shall
constitute personal service thereof.

      Section 8.7.  Entire Agreement.
                    ----------------

      This  Agreement  constitutes  the entire  agreement  among the parties and
supersedes any prior agreement or  understanding  among them with respect to the
subject matter hereof.

                  [Remainder of Page Intentionally Left Blank]



                                       18
<PAGE>



      IN WITNESS WHEREOF,  the parties hereto have executed this Agreement as of
the date first above written.

                                   GENETIC VECTORS, INC.

                                   By:______________________________________

                                   Name:____________________________________

                                   Title:___________________________________


                                   ORBITER FUND, LTD.

                                   By:______________________________________

                                   Name:____________________________________

                                   Title:___________________________________





                                       19
<PAGE>


                                    EXHIBIT 1

                                PLEDGED PROPERTY