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February 7, 2003

MedImmune Responds to FluMist(TM) Complete Response Letter

GAITHERSBURG, Md., Feb 7, 2003 /PRNewswire-FirstCall via COMTEX/ -- MedImmune, Inc. (Nasdaq: MEDI) announced today that it has completed the submission of information requested by the U.S. Food and Drug Administration (FDA) for FluMist(TM) (Influenza Virus Vaccine Live, Intranasal), an influenza vaccine delivered as a nasal mist. The information submitted responds to the five questions raised by the FDA in a Complete Response Letter issued on January 29, 2003.

If approved by the FDA, FluMist would be the first and only intranasal influenza vaccine in the United States, and would be marketed by MedImmune and Wyeth Pharmaceuticals, a division of Wyeth (NYSE: WYE) as part of an ongoing global collaboration agreement.

FluMist is a live, attenuated vaccine delivered as a nasal mist being developed by MedImmune for the prevention of influenza. Clinical trials suggest that FluMist is effective in reducing the incidence of influenza in healthy children and adults. FluMist also offers certain potential advantages in its administration by nasal spray, such as eliminating the unpleasantness of needle-based injectable vaccines and local injection site reactions.

Influenza is the most common cause of medically attended acute respiratory illness in the U.S. often involving fever, chills, muscle weakness, cough, sore throat, nasal congestion, headache and general malaise. According to the Centers for Disease Control and Prevention and the American Lung Association, 20 to 50 million people are infected annually in the U.S., causing 70 million lost work days(1), 38 million lost school days(2), and 20,000 to 50,000 deaths per year (primarily in the elderly)(3). The annual burden of the disease to society has been estimated at $15 billion.

MedImmune is a leading biotechnology company focused on researching, developing and commercializing products to prevent or treat infectious disease, autoimmune disease and cancer. MedImmune actively markets three products, Synagis(R) (palivizumab), Ethyol(R) (amifostine) and CytoGam(R) (cytomegalovirus immune globulin intravenous (human)), and has several products in clinical testing. MedImmune employs approximately 1,600 people, is headquartered in Gaithersburg, Maryland, and has additional operations in Frederick, Maryland, as well as Pennsylvania, California, the United Kingdom and the Netherlands. For more information on MedImmune and full prescribing information for the company's marketed products, visit the company's website at http://www.medimmune.com .

    1 Adams PF, Hendershot GE, Marano MA.  Current estimates from the National
      Health Interview Survey, 1996 National Center for Health Statistics.
      Vital Health Sta. 10(200) 1999
    2 Adams PF, Hendershot GE, Marano MA.  Current estimates from the National
      Health Interview Survey, 1996 National Center for Health Statistics.
      Vital Health Sta. 10(200) 1999
    3 CDC.  ACIP/MMWR. 2002; 51 (no, RR-3):1-31
This announcement may contain, in addition to historical information, certain forward-looking statements that involve risks and uncertainties, including risks and uncertainties surrounding the potential approval, launch and successful acceptance of FluMist in the marketplace. Such statements reflect management's current views and are based on certain assumptions. Actual results could differ materially from those currently anticipated as a result of a number of factors, including risks and uncertainties discussed in the company's filings with the U.S. Securities and Exchange Commission. The company is developing several products for potential future marketing. There can be no assurance that such development efforts will succeed, that such products will receive required regulatory clearance or that, even if such regulatory clearance were received, such products would ultimately achieve commercial success.

SOURCE MedImmune, Inc.

CONTACT:          William Roberts, Manager, Investor Relations, +1-301-527-4358,
                  or Jamie Lacey, Associate Director, Public Relations, +1-240-632-4035, both of
                  MedImmune, Inc.

URL:              http://www.medimmune.com
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