Document:

<PAGE>

                                                                    Exhibit 10.8

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

                                       1
                                                                  EXECUTION COPY
                                                                  --------------

              THIRD AMENDMENT TO EXCLUSIVE LICENSE AGREEMENT (#4)
              ---------------------------------------------------

     This Third Amendment, effective this 10th day of February 1999, is made and
entered into by and between the New York Blood Center, Inc. ("NYBC"), a New York
not-for-profit corporation, having an office at 310 east 67th Street, New York,
New York 10021 and V.I. Technologies, Inc. (formerly known as Melville
Biologics, Inc.) a Delaware corporation, having an office at 155 Duryea Road,
Melville New York 11747 ("LICENSEE").

     WHEREAS, NYBC and LICENSEE entered into an Exclusive License Agreement (#4)
for Virally Inactivated Fibrin Sealant/Thrombin Products, effective October 26,
1995 and thereafter entered into an Amendment dated September 27, 1996, and a
Second Amendment dated January 1, 1998 (collectively the "Agreement"); and

     WHEREAS, the parties wish to make further changes to the Agreement.

     NOW THEREFORE, in consideration of the mutual covenants contained in the
Agreement and in this Third Amendment and other good and valuable consideration
the receipt and sufficiency of which is hereby acknowledged, the parties agree
as follows:

     1.  Paragraph 3.6 of the Agreement is hereby deleted and replaced with the
following:

     NYBC agrees that in lieu of (a) filing an application to sell PRODUCT in
the U.S.A. with the appropriate government agency, or (b) paying NYBC
***************************** ******************* no later than December 31,
1998, LICENSEE shall pay to NYBC
************************************************* in three installments as
follows: a first installment of ***************************** due no later than
January 4, ****, a

                                       1
<PAGE>

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

second installment of *****************************  due no later than April 1,
**** and a Third Installment of *****************************  due no later than
July 1, ****.  NYBC agrees that if LICENSEE makes the payments set forth in this
Paragraph, LICENSEE shall retain the exclusive license granted to it pursuant to
Paragraph 2.1.

     2.  This Third Amendment shall be deemed incorporated into the Agreement in
full and to be an integral part thereof as though fully set forth therein.  With
the exception of this Third Amendment, all other provisions of the Agreement
shall remain in full force and effect.

     IN WITNESS WHEREOF, the parties have caused this Third Amendment to be
executed as of the Effective Date.

NEW YORK BLOOD CENTER      V.I. TECHNOLOGIES, INC.

By:                        By:
   --------------------       --------------------

Name:                      Name:
     ------------------         ------------------

Title:                     Title:
      -----------------          -----------------

                                       2<PAGE>

                                                                   Exhibit 10.10

                                                                         V VITEX

February 16, 2000

By Facsimile and Certified Mail

Mark DeWyngaert
Director, Office of Patents & Licenses
Commercial Development
The New York Blood Center, Inc.
310 E. 67th Street
New York, NY 10021-6295

Re:  Exclusive License Agreement (#5) for Virally Inactivated Cellular Products

Dear Mark,

Pursuant to Section 10.5 of the Exclusive License Agreement (#5) for Virally
Inactivated Cellular Products between The New York Blood Center, Inc. ("NYBC")
and V.I. Technologies, Inc. ("Vitex"), dated September 21, 1995, as amended
("Agreement"), Vitex hereby notifies NYBC that it is terminating the Agreement
effective February 1, 2000.

VITEX will return all know-how related to phthalocyanines to NYBC.

Should you have any questions regarding this matter, please contact me at
617.864.4800 x240.

Sincerely,

/s/ Yukari Y. Perrella
Yukari Y. Perella
Director, Business Development

cc:  General Counsel, The New York Blood Center, Inc.
     John Barr, VITEX
     Tom Higgins, VITEX
     Frank Pascale, Pall Corporation<PAGE>

                                                                   EXHIBIT 10.11

             FIRST AMENDMENT TO APPENDIX A OF THE LICENSE AGREEMENTS
                   BETWEEN THE NEW YORK BLOOD CENTER, INC. AND
        MELVILLE BIOLOGICS, INC. (NOW V.I. TECHNOLOGIES, INC., OR VITEX)

     This First Appendix A Amendment, effective January 1, 1999, is made and
entered into by and between The New York Blood Center, Inc. ("NYBC"), a New York
not-for-profit corporation, having an office at 310 East 67th Street, New York,
NY 10021 and V.I. Technologies, Inc. (formerly known as Melville Biologics,
Inc.), a Delaware corporation, having an office at 155 Duryea Road, Melville, NY
11747 ("LICENSEE").

     WHEREAS, NYBC and LICENSEE are parties to the following License Agreements:

     a.   Non-Exclusive License Agreement (#1) For Solvent Detergent Treated
Blood Derived Therapeutic Products ("Agreement #1").

     b.   Non-Exclusive License Agreement (#2) For UV Treated Blood Derived
Therapeutic Products ("Agreement #2").

     c.   Exclusive License Agreement (#3) For Virally Inactivated Transfusion
Plasma Products ("Agreement #3").

     d.   Exclusive License Agreement (#4) For Virally Inactivated Fibrin
Sealant/Thrombin Products ("Agreement #4").

     e.   Exclusive License Agreement (#5) For Virally Inactivated Cellular
Products ("Agreement #5").

     WHEREAS, the parties wish to revise and update Appendix A of each of
Agreements #1 through #5 with respect to the listing of PATENT RIGHTS therein;

     NOW, THEREFORE, in consideration of the mutual covenants contained in
Agreements #1 through #5 and other good and valuable consideration, the receipt
and sufficiency of which is hereby acknowledged, the parties agree as follows:

     1.   The listing of PATENT RIGHTS in Appendix A of Agreement #1 is hereby
deleted and replaced with the listing entitled Appendix A annexed hereto as
Exhibit 1.
<PAGE>

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

     2.   The listing of PATENT RIGHTS in Appendix A of Agreement #2 is hereby
deleted and replaced with the listing entitled Appendix A annexed hereto as
Exhibit 2.

     3.   The listing of S/D PATENT RIGHTS, UV PATENT RIGHTS and UNIVERSAL
PATENT RIGHTS in Appendix Al, A2, and A3 of Agreement #3 is hereby deleted and
replaced with the listings entitled Appendix Al, A2, and A3 annexed hereto as
Exhibit 3.

     4.   The listing of S/D PATENT RIGHTS, UV PATENT RIGHTS and PRODUCT PATENT
RIGHTS in Appendix Al, A2, and A3 of Agreement #4 is hereby deleted and replaced
with the listings entitled Appendix Al, A2, and A3 annexed hereto as Exhibit 4

     5.   The listing of PATENT RIGHTS in Appendix A of Agreement #5 is hereby
deleted and replaced with the listing entitled Appendix A annexed hereto as
Exhibit 5.

     6.   The description of KNOW-HOW in Appendix A of each of Agreements #1
through #3 and #5 is unchanged.

     7.   The description of KNOW-HOW in Appendix A of Agreement #4 is revised
to eliminate the reference to ****.

     IN WITNESS WHEREOF, the parties hereto have entered into and executed this
First Appendix A Amendment on the date first above written.

NEW YORK BLOOD CENTER, INC.        V.I. TECHNOLOGIES, INC.

By:                                By:   /s/ John R. Barr
   --------------------               -----------------------

Name:                              Name:  John R. Barr
   --------------------                 ---------------------

Title:                             Title:  President and CEO
   --------------------                  --------------------

                                       2
<PAGE>

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

                          Appendix A - Agreement No. 1
                                 Patent Rights

**** [Six pages omitted] ****
<PAGE>

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

               AGREEMENT NO. 2 UV TREATED BLOOD DERIVED PRODUCTS
               -------------------------------------------------
                              APPENDIX A - PATENTS
                              --------------------

**** [Seven pages omitted] ****
<PAGE>

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

APPENDIX A:  PATENT RIGHTS

                        APPENDIX A - 1 - Agreement No. 3

                                 PATENT RIGHTS

**** [Four pages omitted] ****
<PAGE>

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

                AGREEMENT NO. 3 VIRALLY INACTIVATED TRANSFUSION
                -----------------------------------------------
                                PLASMA PRODUCTS
                                ---------------
                             APPENDIX A2 - PATENTS
                             ---------------------

**** [Five pages omitted] ****
<PAGE>

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

            AGREEMENT NO. 3       VIRALLY INACTIVATED TRANSFUSION
            ------------  -----------------------------------------
                                PLASMA PRODUCTS
                                ---------------
                            APPENDIX A3   -  PATENTS
                            ------------------------

**** [Two pages omitted] ****
<PAGE>

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

                                  APPENDIX A-1

                                 PATENT RIGHTS

**** [Six pages omitted] ****
<PAGE>

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

           AGREEMENT NO. 4       VIRALLY INACTIVATED FIBRIN SEALANT/
           ---------------------------------------------------------
                               THROMBIN PRODUCTS
                               -----------------
                            APPENDIX A-2   - PATENTS
                            ------------------------

**** [Seven pages omitted] ****
<PAGE>

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

               AGREEMENT NO. 4 VIRALLY INACTIVATED FIBRIN SEALANT/
               ---------------------------------------------------
                                THROMBIN PRODUCTS
                                -----------------
                             APPENDIX A-3 - PATENTS
                            ------------------------

**** [Four pages omitted] ****
<PAGE>

["****" indicates material omitted and filed separately with the Securities and
Exchange Commission Pursuant to a request for confidential treatment.]

          AGREEMENT NO. 5       VIRALLY INACTIVATED CELLULAR PRODUCTS
          -----------------------------------------------------------
                              APPENDIX A - PATENTS
                              --------------------

**** [Fourteen pages omitted] ****

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00006-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00006-of-00352.parquet"}], [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00006-of-00352.parquet"}]]