EXHIBIT 10.38
                                  -------------

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

         THIS PLEDGE AND SECURITY  AGREEMENT,  dated as of November 19, 1999, 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 $200,000;

         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  purchase 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  for 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 (and signed by Pledgor),  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  Borrower 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

                                       2
<PAGE>

Pledgor to Pledgee in and to the Pledged  Collateral is subject to the rights of
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.  Simultaneously  with the  execution  and
delivery of this  Agreement,  Pledgor shall make,  execute,  acknowledge,  file,
record and deliver to Pledgee such documents and instruments, including, without
limitation, financial 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:

                    (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


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<PAGE>

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"):

                    (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;

                                       4
<PAGE>

                    (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
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,

                                       5
<PAGE>

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


                                       6
<PAGE>

         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
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.


                                       7
<PAGE>

                                   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 the Holder may  declare  the  principal  amount to be due and  payable
immediately,  by a  notice  in  writing  to  the  Company,  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 any Holder.

                (b) Upon the  occurrence  of an Event  of  Default,  the  Holder
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 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

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<PAGE>

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  the  Holder  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.

            (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,

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<PAGE>

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
the Holder 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 the Holder 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.
                      ---------------

            (a)  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,  the Holder  (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 the Holder shall have made
any demand on 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:


                                       10
<PAGE>

                (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 the Holder  (including any claim for the reasonable legal fees and
expenses and other expenses paid or incurred by the Holder  permitted  hereunder
and of the Holder 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 each Holder to make such payments to the Holder and, in the event
that the Holder  shall  consent to the making of such  payments  directed to the
Holder,  to pay to the Holder any amounts for  expenses  due it  hereunder.

            (b) Nothing herein contained shall be deemed to authorize the Holder
to authorize,  consent to or accept or adopt on behalf of any Holder any plan of
reorganization,  arrangement,  adjustment or composition affecting the rights of
any Holder thereof or to authorize the Holder to vote in respect of the claim of
any  Holder  in any  such  proceeding.

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<PAGE>

         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.

                                   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


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<PAGE>

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.

         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 the Holder
or  beneficiary  thereof;

            (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.


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<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

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<PAGE>

Collateral,  each  against all manner of claims and demands on a timely basis to
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  or the  conversion  of all of the Note as  provided
therein;  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,  or such conversion of the


                                       17
<PAGE>

Note,  Pledgor shall be entitled to the return,  at its expense,  of such of the
Pledged  Collateral  as shall not have been sold,  returned 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.


                                       18
<PAGE>

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

                                  GENETIC VECTORS, INC.

                                  By:
                                     -------------------------------------------
                                  Title:
                                        ----------------------------------------

                                  ORBITER FUND, LTD.

                                  By:
                                     -------------------------------------------
                                  Title:
                                        ----------------------------------------



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