[Novavax Letterhead]

September 10, 1998 (as amended by letter dated September 25, 1998)

Richard F. Maradie
325 Epping Way
Annapolis, MD 21401

Dear Rick:

This letter contains information regarding your separation from employment with
Novavax on September 4, 1998. The Company has agreed to offer you separation
benefits as summarized below.

Separation Pay

You have been paid through September 4, 1998, and you will be paid two weeks in
lieu of notice in your last paycheck. If you sign your separation agreement and
your period of revocation has expired, you will receive 50 weeks of separation
pay, not including the two weeks pay in lieu of notice, at your base
compensation rate.

Medical and Dental Benefits

Your medical, dental and vision coverage with Great West will end on September
30, 1998. Information on extending this coverage through COBRA is attached. Your
COBRA payments will be paid by Novavax for a period of one year from October 1,
1998 through September 30, 1999.

Life Insurance And Disability

Your group term life insurance policy will end on September 30, 1998. You may
convert to an individual policy, as described in the information attached. Your
short and long term disability coverage will end as of September 4, 1998.

401(k) Savings Plan

Our records indicate that you are participating in the Employee Savings and
Investment Plan. There is information attached describing your distribution
options for funds currently in your account. Please be aware that you have 60
days from the date you receive this information to chose a distribution option.

Manchester Transition Program

Novavax has negotiated a contract for outplacement support with a Career
Consultant to assist you during the transition process. Your six month program
begins with your first appointment on Monday September 21, 1998 at 9:00 a.m.
Documentation is required.

Legal Services

Novavax has agreed to cover a maximum of $5,000.00 in costs for legal counsel
regarding corporate indemnification. Invoices from the attorney should be
submitted directly to Novavax.

If you have any questions relating to any of the benefits described above,
please contact me.

Sincerely,
/s/ Brenda Fugagli
Brenda Fugagli
Executive Vice President and COO
enclosures


<PAGE>   2

                                  NOVAVAX, INC.

                        SEPARATION AND RELEASE AGREEMENT

Novavax, Inc. and Richard F. Maradie hereby agree the following sets out the
complete agreement and understanding regarding the termination of my employment
with Novavax, Inc. (the "Company" or "Novavax"), which shall be effective
September 4, 1998.

1.     I hereby acknowledge that the separation compensation offered to me has
       been explained. I also acknowledge that I have been given at least
       twenty-one (21) days to review Novavax' Separation and Release Agreement
       ("Agreement") required for my receipt of separation benefits. I certify
       that I have been advised in writing to consult an attorney, and that I
       have had the opportunity to obtain all advice and information deemed
       necessary with respect to the matters covered by this Agreement,
       including the opportunity to consult with legal counsel or anyone else of
       my choosing.

2.     In consideration for the separation benefits I am eligible to receive, as
       described to me by letter dated September 10, 1998 as amended September
       25, 1998:

       (i)     I agree not to take any action which disparages or criticizes the
               Company, its management, or its practices or which disrupts or
               impairs its normal operations, including actions that would
               result in the filing of any claims, lawsuits or charges against
               the Company as a result of anything which has occurred up to and
               including the present date.

       (ii)    I also understand and agree that the Company may terminate my
               continued eligibility for separation benefits and immediately
               recover all benefits previously paid to me if I engage in
               misconduct or otherwise violate Company policy, including, but
               not limited to any action that violates this Agreement or harms
               the reputation of the Company with its customers, suppliers or
               the public; interferes with existing contractual or employment
               relationships with customers, suppliers or Company employees; or
               misappropriates, misuses, or discloses any trade secret or other
               confidential information I learned while actively employed by the
               Company.

       (iii)   In addition, and in further consideration of my eligibility for
               the separation pay and benefits described to me, the sufficiency
               of which consideration I acknowledge, I hereby agree to release
               and discharge the Company, its affiliate corporations, and all of
               its officers, directors, employees, agents and attorneys from any
               and all losses, expenses, claims, rights, entitlements, whether
               known or unknown, I now have or have had or may later claim to
               have had arising out of any alleged violation of my rights while
               employed by the Company, including but not limited to, claims for
               back pay, for reinstatement or for recovery of any losses or
               other damages to me or my property resulting from any alleged
               violation of local, state or federal law, such as (but not
               limited to) claims arising under Title VII of the Civil Rights
               Act of 1964, 42 U.S.C. Section 200 et seq. (prohibiting
               discrimination on account of race, sex, national origin or
               religion); the Age Discrimination in Employment Act of 1967, 29
               U.S.C. Section 621 et seq. (prohibiting discrimination on account
               of age), the Americans with Disabilities Act of 1990, 42 U.S.C.
               Section 12, 101 et seq., (prohibiting discrimination on account
               of disabilities), or any similar federal, state, or local law
               relating to my employment.

       (iv)    I will not hereafter pursue any individual claim against the
               Company, its affiliated corporations, or any of its officers,
               directors, employees or agents, by filing a lawsuit in any local,
               state or federal court for or on account of anything which has
               occurred up to the present time as a result of my previous
               employment.


<PAGE>   3

3.     I understand that I may revoke this Agreement entirely by delivering a
       signed notice of revocation to the Company within seven (7) days after I
       sign this Agreement. In that event, this Agreement will be canceled and
       void, I will not be entitled to any of the separation benefits provided
       by this Agreement, and neither party to this Agreement shall have any
       rights or obligations arising under it.

4.     This Agreement shall be binding upon and shall be for the benefit of the
       Company and myself, as well as our respective heirs, personal
       representatives, successors and assigns.

5.     The provisions of this Agreement shall be severable, and the invalidity
       of any provision shall not affect the validity of other provisions.

6.     I have carefully read this Agreement, I understand its meaning and
       intent, I have not been coerced into signing this Agreement, and I
       voluntarily agree to abide by its terms. I acknowledge that the
       separation benefits described in this Agreement are adequate
       consideration for my signing it and that no other promise or agreement of
       any kind has been made to me by the Company to cause me to execute this
       Agreement and that the only consideration for my execution of this
       Agreement is set forth in this document.


/s/ Richard F. Maradie                                 9/22/98
- --------------------------------                     ----------------------
Employee Signature                                   Dated

For Novavax,
In exchange for the employee's execution of this release, the Company promises
to provide separation benefits as described to him or her.



Witnessed: /s/ Sally Kiernan                         Dated:    9/22/98
          --------------------------                        ---------------

NOTE: This Agreement must be signed, dated and returned to the Company without
any alternation. Any modification or alternation of any terms of this Agreement
will void the Agreement in its entirety.

Source: OneCLE Business Contracts.