<PAGE>

                                                               EXHIBIT 10.101(2)


                           RSVIG TERMINATION AGREEMENT

                  RSVIG Termination Agreement made this 17th day of December
1999 by and between MEDIMMUNE, INC., a Delaware corporation ("MedImmune"), and
WYETH - AYERST PHARMACEUTICALS, INC. ("WYETH"), a New York corporation and a
wholly-owned subsidiary of AMERICAN HOME PRODUCTS CORPORATION, a Delaware
corporation ("AHP").

                  WHEREAS MedImmune and American Cyanamid Company entered into a
RSVIG Co-Development and Co-Promotion Agreement, dated November 8, 1993, as
amended October 26, 1995 (the "RSVIG Agreement"); and

                  WHEREAS American Cyanamid Company was acquired by AHP in 1994;
and

                  WHEREAS the parties wish to terminate the RSVIG Agreement on
the terms set forth below;

                  NOW THEREFORE, the parties hereby agree as follows:

1.   Wyeth agrees to pay on the date hereof and MedImmune agrees to accept an
     amount equal to (CONFIDENTIAL TREATMENT HAS BEEN REQUESTED) (U.S.) in full
     satisfaction of all duties, obligations and responsibilities of Wyeth under
     the RSVIG Agreement ("Termination Payment"), subject, however, to the
     provisions of Paragraph 5 of this Agreement. Such Termination Payment shall
     be wire transferred to MedImmune's account (CONFIDENTIAL TREATMENT HAS BEEN
     REQUESTED) for credit to MedImmune, Inc., (CONFIDENTIAL TREATMENT HAS BEEN
     REQUESTED) (payment per RSVIG Termination Agreement).

2.   Simultaneously with the execution of this Agreement, (a) MedImmune will
     execute and deliver to WYETH a release in the form attached hereto as
     Exhibit A; and (b) WYETH will execute and deliver to MedImmune a release in
     the form attached hereto as Exhibit B.

3.   WYETH represents that there are no claims, demands or causes of action
     pending against it or any of its subsidiaries or affiliates that would
     entitle it to be indemnified under Article 6 of the RSVIG Agreement and, to
     the best of its knowledge, no such claim, demand or cause of action is
     threatened.

4.   MedImmune represents that there are no claims, demands or causes of action
     pending against it or any of its subsidiaries or affiliates that would
     entitle it to be indemnified

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     under Article 6 of the RSVIG Agreement and, to the best of its knowledge,
     no such claim, demand or cause of action is threatened.

5.   The RSVIG Agreement is terminated as of the date hereof. Notwithstanding
     Section 8.2 of the RSVIG Agreement regarding survival of certain provisions
     of the RSVIG Agreement upon termination thereof, the parties agree that
     only Sections 4.2(f) (only with respect to Product (defined, for purposes
     of this Agreement, in the same manner as in the RSVIG Agreement) sold to
     the ultimate consumer prior to the date hereof), 4.4(f) (only with respect
     to Product sold to the ultimate consumer prior to the date hereof), Article
     6 (only to the extent provided in Paragraphs 6 and 7 of this Agreement),
     and Sections 9.6 and 9.11 of the RSVIG Agreement shall survive termination
     thereof.

6.   Additionally, Section 9.12 of the RSVIG Agreement shall survive
     termination, provided however, such Section 9.12 shall not apply in the
     event 1) Wyeth and/or American Home Products Corporation transfers or sells
     all or substantially all of its business to which the Agreement relates or
     2) of a merger or consolidation, change of control or other similar
     transaction involving Wyeth and/or American Home Products Corporation.

7.   With respect to occurrences prior to the date hereof, Article 6 of the
     RSVIG Agreement shall continue in full force and effect.

8.   With respect to occurrences on or after the date hereof, MedImmune shall
     indemnify, defend and hold harmless Wyeth, American Home Products
     Corporation and their respective directors, officers, agents and employees
     (the "Indemnified Party") from and against any and all liability, loss,
     damages, expenses (including attorney fees) relating to the RSVIG Agreement
     and/or the Product, provided MedImmune shall not be obligated to indemnify
     to the extent any such claims result from a material misrepresentation or
     willful conduct on the part of the Indemnified Party and provided, further,
     that the Indemnified Party has complied with the provisions of Section 6.2
     of the RSVIG Agreement.

9.   Termination of the RSVIG Agreement will not alter the rights or obligations
     of the parties with respect to the RSV MAB Termination Agreement, dated
     October 26, 1995, between MedImmune and American Cyanamid Company, or the
     RSV Vaccine Termination Agreement, dated October 26, 1995, between
     MedImmune and American Cyanamid Company, each of which shall remain in full
     force and effect.

10.  The RSVIG Agreement is being terminated by mutual agreement of the parties
     and not as a result of a breach of the RSVIG Agreement.

11.  Following the date hereof, Wyeth shall have no rights whatsoever in the
     Product, including but not limited to any rights to co-promote the Product
     or to any earnings related to the Product. Wyeth will return to MedImmune
     any existing stock of the


                                       2
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     Product and any marketing or other materials relating to the Product that
     is in its possession.

12.  MedImmune and Wyeth, their representatives, agents and counsel agree to
     maintain the confidentiality of the terms of this Agreement, except to the
     extent otherwise required by law and provided that in such instances, the
     disclosing party shall to the fullest extent permitted by such laws,
     request that confidential treatment be afforded this Agreement.





                  IN WITNESS WHEREOF, this RSVIG Termination Agreement has been
duly executed effective on the date first above written.



                                    MEDIMMUNE, INC.

                                    By:  /s/ Melvin D. Booth
                                    -------------------------------
                                    Name: Melvin D. Booth
                                    Title:   President




                      WYETH - AYERST PHARMACEUTICALS, INC.



                                    By:  /s/ Kevin Reilly
                                    -------------------------------
                                    Name: Kevin Reilly
                                    Title:   President



                                       3
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                                                                      EXHIBIT A

                                     RELEASE

                  WYETH - AYERST PHARMACEUTICALS, INC., a Delaware corporation
("Releasor"), in consideration of the promises, covenants and agreements set
forth in the RSVIG Termination Agreement, dated December 17, 1999, entered into
between Releasor and MEDIMMUNE, INC., a Delaware corporation ("Releasee"),
hereby releases and discharges Releasee and its successors and assigns from any
and all claims, demands, causes of action, obligations, damages, losses, costs
and liabilities of any nature whatsoever, whether or not now known, suspected or
claimed, which Releasor ever had, now has or claims to have against Releasee
arising from or relating to the RSVIG Co-Development and Co-Promotion Agreement,
dated November 8, 1993, as amended October 26, 1995, between Releasee and
American Cyanamid Company, except as otherwise provided in the aforesaid RSVIG
Termination Agreement.

                  IN WITNESS WHEREOF, Releasor has executed this Release on the
day and year written below.



                      WYETH - AYERST PHARMACEUTICALS, INC.




                                    By:  /s/ Kevin Reilly
                                    -------------------------------
                                    Name:   Kevin Reilly
                                    Title:  President


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                                                                       EXHIBIT B

                                     RELEASE

                  MEDIMMUNE, INC., Delaware corporation ("Releasor"), in
consideration of the promises, covenants and agreements set forth in the RSVIG
Termination Agreement, dated December 17, 1999, entered into with WYETH - AYERST
PHARMACEUTICALS, INC., a Delaware corporation ("Releasee"), hereby releases and
discharges Releasee and its respective successors and assigns from any and all
claims, demands, causes of action, obligations, damages, losses, costs and
liabilities of any nature whatsoever, whether or not now known, suspected or
claimed, which Releasor ever had, now has or claims to have against Releasee
arising from or relating to the RSVIG Co-Development and Co-Promotion Agreement,
dated November 8, 1993, as amended October 26, 1995, between Releasor and
American Cyanamid Company, except as otherwise provided in the aforesaid RSVIG
Termination Agreement.

                  IN WITNESS WHEREOF, Releasor has executed this Release on the
day and year written below.

                                    MEDIMMUNE, INC.

                                    By:  /s/ Melvin D. Booth
                                    -------------------------------
                                    Name: Melvin D. Booth
                                    Title:   President