Edgar Filing: MEDIMMUNE INC /DE

AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON SEPTEMBER 5, 2002
Registration No. 333-76844
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SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

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AMENDMENT NO. 2
TO
FORM S-3
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

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MEDIMMUNE, INC.
(Exact name of registrant as specified in its charter)

DELAWARE 2836
(State or other jurisdiction of Primary Standard Industrial
incorporation or organization) Classification Code)

52-155759
(I.R.S. Employer
Identification No.)
35 WEST WATKINS MILL ROAD
GAITHERSBURG, MARYLAND 20878
TELEPHONE: (301) 417-0770
(Address, including zip code, and telephone number, including area code, of
registrant's principal executive offices)
DAVID M. MOTT
CHIEF EXECUTIVE OFFICER AND VICE CHAIRMAN
35 WEST WATKINS MILL ROAD
GAITHERSBURG, MARYLAND 20878
TELEPHONE: (301) 417-0770
(Name, address, including zip code, and telephone number, including area code,
of agent for service)
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COPY TO:
FREDERICK W. KANNER
DEWEY BALLANTINE LLP
1301 AVENUE OF THE AMERICAS
NEW YORK, NEW YORK 10019
TELEPHONE: (212) 259-8000
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APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: FROM TIME TO
TIME AFTER THE EFFECTIVE DATE OF THIS REGISTRATION STATEMENT.
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If the only securities being registered on this form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box. / /

If any of the securities being registered on this form are to be offered
on a delayed or continuous basis pursuant to Rule 415 under the Securities Act
of 1933, other than securities offered only in connection with dividend or
interest reinvestment plans, check the following box. /X/

If this form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering. / /

If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, please check the following box and list the Securities
Act registration statement number of the earlier effective registration
statement for the same offering. / /

If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. / /
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THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(A),
MAY DETERMINE.

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PROSPECTUS
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3,859,250 SHARES

MEDIMMUNE, INC.

COMMON STOCK
(PAR VALUE $0.01 PER SHARE)

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This prospectus relates to (i) an aggregate of up to 419,250 shares of
MedImmune, Inc. common stock that may be issued upon exercise of the common
stock purchase warrants issued by Aviron and (ii) an aggregate of up to
3,440,000 shares of MedImmune common stock that may be issued upon conversion of
the $200,000,000 5 1/4% Convertible Subordinated Notes Due 2008 of Aviron. As a
result of the acquisition of Aviron by MedImmune in January 2002, each share of
Aviron common stock underlying the warrants and convertible notes referred to
above is now convertible into 1.075 shares of MedImmune common stock, subject to
further adjustment as described herein. See "Plan of Distribution."

MedImmune stock is listed on the Nasdaq National Market under the
symbol "MEDI." On September 4, 2002, the closing price of MedImmune stock was
$25.45 per share.

SEE "RISK FACTORS" BEGINNING ON PAGE 5 OF THIS PROSPECTUS FOR A
DISCUSSION OF FACTORS THAT SHOULD BE CONSIDERED BY INVESTORS IN CONNECTION WITH
AN INVESTMENT IN MEDIMMUNE STOCK.

Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or determined if this
prospectus is truthful or complete. Any representation to the contrary is a
criminal offense.

The date of this prospectus is September 5, 2002

TABLE OF CONTENTS

INFORMATION ABOUT MEDIMMUNE..............................................................................4

RISK FACTORS.............................................................................................6

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS.......................................................13

MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES...........................................................14

USE OF PROCEEDS.........................................................................................16

PLAN OF DISTRIBUTION....................................................................................16

WHERE YOU CAN FIND MORE INFORMATION.....................................................................17

LEGAL OPINIONS..........................................................................................19

EXPERTS.................................................................................................19

In this prospectus, "we," "us" and "our" refers to MedImmune, Inc. and
its subsidiaries. You should rely only on the information contained in this
prospectus or incorporated into this prospectus by reference. We have not
authorized anyone to provide you with information different from that contained
in this prospectus. We are offering to sell, and seeking offers to buy, shares
of common stock only in jurisdictions where offers and sales are permitted. The
information contained in this prospectus is accurate only as of the date of this
prospectus, regardless of the time of delivery of this prospectus or of any sale
of the MedImmune stock. You should read this entire prospectus and any
accompanying prospectus supplement carefully, including the "Risk Factors"
section, and the documents, including the financial statements and notes to
those statements, incorporated by reference in this prospectus.

Synagis, CytoGam, Ethyol, RespiGam, Vitaxin and NeuTrexin are registered
trademarks of the Company. FluMist and Numax are trademarks of the Company.

INFORMATION ABOUT MEDIMMUNE

MedImmune was founded in 1988 and is a biotechnology company
headquartered in Gaithersburg, Maryland with five products on the market and a
diverse product portfolio. MedImmune is focused on using advances in immunology
and other biological sciences to develop important new products that address
significantly unmet medical needs in areas of infectious disease and immune
regulation. MedImmune also focuses on oncology through its wholly-owned
subsidiary, MedImmune Oncology, Inc. (formerly U.S. Bioscience, Inc.), acquired
in November 1999.

In January 2002, MedImmune completed its acquisition of Aviron, which
has been renamed MedImmune Vaccines, Inc. MedImmune Vaccines is focused on
prevention of disease through innovative vaccine technologies. Its lead
product candidate is FluMist, a live, attenuated virus vaccine delivered as a
nasal mist for the prevention of influenza. FluMist is currently being
reviewed by the FDA.

In 1998, MedImmune launched SYNAGIS in the United States for the
prevention of respiratory syncytial virus (RSV) in high-risk pediatric patients.
Synagis is the first and only monoclonal antibody approved for an infectious
disease and has become an important new pediatric product for the prevention of
RSV, the leading cause of viral pneumonia and bronchiolitis in infants and
children.

MedImmune also markets four other products:

o CYTOGAM is marketed for prophylaxis against cytomegalovirus (CMV)
associated with transplantation of kidney, lung, liver, pancreas
and heart. CMV contributes significantly to morbidity and
mortality in organ transplant recipients and can cause severe
pneumonia and other organ complications related to invasive CMV
disease which, if not successfully treated, can lead to organ
failure.

o ETHYOL, marketed through MedImmune Oncology's sales and marketing
group, is indicated for the reduction of cumulative renal toxicity
associated with repeated administration of cisplatin in patients
with advanced ovarian cancer or non-small cell lung cancer. It is
also indicated for the reduction of the incidence of
moderate-to-severe xerostomia (chronic dry mouth) in patients
undergoing post-operative radiation treatment for head and neck
cancer. Patients with xerostomia are at increased risk of oral
infection, dental cavities and loss of teeth and often have
difficulty chewing, swallowing and speaking.

o NEUTREXIN, also marketed by MedImmune Oncology, is indicated for
treatment of moderate-to-severe PNEUMOCYSTIS CARINII PNEUMONIA
(PCP) in immunocompromised patients, including patients with AIDS,
who are intolerant of or refractory to,
trimethoprim-sulfamethoxazole therapy, or for whom
trimethoprimsulfamethoxazole is contraindicated.

o RESPIGAM is indicated for the prevention of serious RSV disease in
children less than 24 months of age with chronic lung disease or a
history of premature birth. RespiGam has largely been replaced by
Synagis in the marketplace.

The Company owns or leases five manufacturing facilities: a multi-use
biologics facility in Frederick, Maryland; a fill and finish facility in
Nijmegen, the Netherlands; a pilot manufacturing facility at its headquarters in
Gaithersburg, Maryland; a filling and packaging plant in Philadelphia,
Pennsylvania; and a bulk supply facility in Speke, England.

RISK FACTORS

Prospective investors should carefully consider the following risk
factors, in addition to the other information included in this prospectus, when
evaluating an investment in MedImmune stock.

THE SEASONAL NATURE OF OUR BUSINESS CAN EXAGGERATE THE CONSEQUENCES OF ANY
FACTOR THAT ADVERSELY AFFECTS OUR SALES AND MAY CAUSE SIGNIFICANT FLUCTUATIONS
IN OUR QUARTERLY OPERATING RESULTS.

Our principal product, Synagis, accounted for approximately 89% of our
total product sales for the year 2001. Synagis is used to protect high-risk
infants from serious lower respiratory tract disease caused by RSV. Because RSV
occurs primarily during the winter months, the major portion of Synagis sales
occur during the first and fourth quarters of the calendar year. This high
concentration of product sales in a portion of the year exaggerates the adverse
consequences on our profits of any manufacturing or supply delays, any inability
to satisfy product demand, or any unsuccessful sales or marketing strategies
during the RSV season and may cause our quarter-to-quarter operating results to
vary widely. Furthermore, our current product base would limit our ability to
offset in the second and third quarters any lower-than-expected Synagis sales
during the RSV season, which could cause our annual financial results to be
below expectations.

IF WE ARE UNABLE TO SUCCESSFULLY COMMERCIALIZE FLUMIST, THE ANTICIPATED BENEFITS
OF OUR ACQUISITION OF AVIRON WILL NOT BE REALIZED.

We acquired Aviron in January 2002 for approximately $1.6 billion of
MedImmune common stock. The principal asset of Aviron is its lead product
candidate, FluMist, which is a vaccine delivered as a nasal mist for the
prevention of influenza. FluMist is not currently approved for marketing, but
its Biologic License Application is pending before the U.S. Food and Drug
Administration ("FDA"). There can be no assurance that the FDA will approve
FluMist for marketing. Even if it were approved for marketing, there can be no
assurance that FluMist would achieve commercial success. We will not realize the
anticipated benefits of the Aviron acquisition unless FluMist achieves
commercial success.

IF WE FAIL TO MANAGE OUR GROWTH PROPERLY, OUR BUSINESS WILL SUFFER.

As a result of our acquisition of Aviron in January 2002 and the recent
expansion of our marketing efforts for Synagis and Ethyol, our workforce has
expanded from 842 employees at January 31, 2001 to 1,519 employees at January
31, 2002. To accommodate our rapid growth and compete effectively, we will need
to continue to improve our management, operational and financial information
systems and controls, generate more revenue to cover a higher level of operating
expenses, integrate Aviron's business and employees into our operations,
continue to attract and retain new employees, accurately anticipate demand for
the products we manufacture and maintain adequate manufacturing capacity. This
rapid growth and increased scope of operations present risks we have not
previously encountered and could result in substantial unanticipated costs and
time delays in product manufacture and development which could materially and
adversely affect our business.

WE HAVE INVESTED HEAVILY IN OUR MANUFACTURING OPERATIONS AND MAY NOT RECOVER
THAT INVESTMENT.

Through December 31, 2001, we have invested over $80.9 million of
capital expenditures in our manufacturing facilities. As a result of our
acquisition of Aviron in January 2002, which leases manufacturing facilities in
Pennsylvania and the United Kingdom, we have increased our investment in
manufacturing facilities by $36.1 million. The Aviron facilities are not yet
licensed by the FDA and we currently have excess capacity in the plasma
production portion of our facility in Frederick, Maryland. If

we suffer manufacturing problems, or are unable to fully utilize our capacity,
we may not recover our investment in these facilities.

WE HAVE ONLY RECENTLY BEGUN SIGNIFICANT MANUFACTURING OPERATIONS. OUR LACK OF
EXPERIENCE CREATES ADDITIONAL RISK OF MANUFACTURING DIFFICULTIES.

Our manufacturing operations, which we have only recently begun on a
commercial scale, expose us to a variety of significant risks, including:

o product defects;

o contamination of product or product loss;

o environmental problems resulting from our production process; and

o inability to manufacture products at a cost that is competitive with
third party manufacturing operations.

Furthermore, we have never produced FluMist on a commercial scale. Our
lack of significant experience in commercial manufacturing may make it more time
consuming or expensive for us to address these problems and could adversely
affect our operations.

WE ARE DEPENDENT ON THIRD PARTY MANUFACTURERS AND SUPPLIERS WHICH MAY NOT
PERFORM AS WE EXPECT.

We are currently, and for the foreseeable future expect to be,
dependent on a limited number of contract manufacturers for some or all of the
manufacture of our current and future products (if any). Although we are able to
produce a portion of the Synagis we sell, we are unable currently to produce all
that we require. Accordingly, we depend on Boehringer Ingleheim Pharma KG ("BI")
to produce a portion of our Synagis requirements. BI's facility is subject to
inspection and approval by both United States and foreign regulatory authorities
in order to maintain its license to manufacture our products. Should BI be
unable to supply Synagis to us for any reason, there can be no assurance that we
would be able to secure an alternate manufacturer on a timely basis, without
increased cost or at all. In addition, since we do not have the capability to
fill and package any of the Synagis we produce at our Frederick Manufacturing
Center, we depend on Chiron Corporation ("Chiron") for that portion of the
manufacturing process. Chiron's facility is similarly subject to inspection and
approval by United States regulatory authorities in order to maintain its
license to fill and package our products. Should Chiron be unable to fill and
package our Synagis for any reason, there can be no assurance that we would be
able to secure an alternate source to fill and package Synagis on a timely
basis, without increased cost or at all.

We depend on the University of Massachusetts, Massachusetts Biologics
Laboratories (the "State Lab") for a portion of the production of our plasma
derived products. The State Lab holds the sole product and establishment
licenses from the FDA for the manufacture of CytoGam and RespiGam. Although we
perform a portion of the CytoGam production process at our Frederick facility,
we rely on the State Lab to manufacture all of the bulk product for CytoGam that
we sell and to produce all of the RespiGam that we sell. We also rely on Aventis
Pasteur to package and fill all of our plasma derived products. Our
manufacturing arrangements with the State Lab are renegotiated annually. We
cannot guarantee that any new arrangements will be made on terms favorable to
us. In addition, we rely on a limited number of suppliers to obtain
substantially all of the plasma used as raw material for the production of
CytoGam and RespiGam. We also depend on third parties to manufacture the drug
substance for Ethyol. There can be no assurance that third party manufacturers
will give our orders

highest priority, or that we would be able to readily find substitute
manufacturers without significant delays or increased costs.

OUR RESEARCH AND DEVELOPMENT ACTIVITIES ARE COSTLY AND MAY NOT BE SUCCESSFUL.

A considerable portion of our annual operating budget is spent on
research, development and clinical activities. In 2001, we spent approximately
$83.0 million on research and development projects, including costs of clinical
trials. We are currently developing numerous products that may never reach
clinical trials, achieve success in the clinic, be submitted to the appropriate
regulatory authorities for approval, or be approved for marketing or
manufacturing by the appropriate regulatory authorities.

Further, we rely on numerous third parties to assist in various stages
of the development process. Third-party contract costs are typically
substantial. In addition, the third party contractors we use may be unable to
complete their work in a timely fashion or in a manner that is satisfactory to
us. Should they be unable to meet our needs, we may have to incur substantial
additional costs, which could have a material adverse effect on our business.

WE ARE DEPENDENT ON THIRD PARTY MARKETING PARTNERS WHICH MAY NOT PERFORM AS WE
EXPECT.

We depend on strategic alliances with our marketing partners to
accomplish many of our sales goals. For example, we have agreements with Abbott
Laboratories under which its Ross Products Division co-promotes Synagis with us
in the United States. If our marketing partners fail to devote sufficient effort
and attention to achieving those goals, our product sales would be adversely
affected.

PATENT PROTECTION FOR OUR PRODUCTS MAY BE INADEQUATE OR COSTLY TO ENFORCE.

We may not be able to obtain effective patent protection for products
we develop. We are currently developing, or considering developing, products in
the biotechnology industry, an industry in which there are extensive patent
filings. The patent position of biotechnology firms generally is highly
uncertain and involves complex legal and factual questions. To date, no
consistent policy has emerged regarding the breadth of claims allowed in
biotechnology patents. Accordingly, there can be no assurance that our patent
applications will result in patents being issued or that, if issued, such
patents will afford protection against competitors with similar technology.
Litigation could be necessary from time to time in order to enforce our
intellectual property rights. There has been substantial litigation regarding
patent and other intellectual property rights in the biotechnology industry. We
are not aware at this time of any infringement of our patents. If we were
required to litigate, there could be substantial cost involved and significant
diversion of our business efforts.

IF WE FAIL TO OBTAIN ANY REQUIRED PATENT LICENSES FROM THIRD PARTIES, OUR
PRODUCT DEVELOPMENT EFFORTS COULD BE LIMITED.

We believe that there are patents issued to third parties and/or patent
applications filed by third parties which could apply to each of our products
and product candidates. These patents and/or applications could limit our
ability to manufacture, use or sell our products. In such a case, we may be
required to obtain a patent license in order to avoid infringing a third party's
intellectual property rights. Such licenses could impose significant royalty
burdens on us. If such a license were necessary, there can be no assurance that
it would be available on terms acceptable to us or at all, which could have a
material adverse effect on our business.

TECHNOLOGICAL DEVELOPMENTS BY OUR COMPETITORS MAY RENDER OUR PRODUCTS OBSOLETE.

If our competitors were to develop superior products or technologies,
our products or technologies could be rendered noncompetitive or obsolete.
Biotechnology and pharmaceuticals are evolving fields in which developments are
expected to continue at a rapid pace. Our success depends upon achieving and
maintaining a competitive position in the development of products and
technologies.

Our lead product, Synagis, is marketed for the prevention of serious
lower respiratory tract disease caused by RSV in pediatric patients at high risk
of RSV. Synagis accounted for approximately 89% of our product sales in 2001. We
are not aware of any competing product being marketed anywhere in the world for
the prevention of RSV disease other than our product RespiGam. Nevertheless,
competition from other biotechnology and pharmaceutical companies can be
intense. Many of our competitors have substantially greater research and
development capabilities, marketing, financial and managerial resources and
experience in the industry. Were a competitor to develop a better product or
technology, our products or technologies could be rendered obsolete, decreasing
our product sales and resulting in a material adverse effect on our business.

COMPLIANCE WITH GOVERNMENT REGULATIONS IS COSTLY AND TIME-CONSUMING.

Substantially all of our products require costly and time-consuming
regulatory approval by governmental agencies. In particular, human therapeutic
and vaccine products are subject to rigorous preclinical and clinical testing
for safety and efficacy and approval processes by the FDA in the United States,
as well as regulatory authorities in foreign countries. There can be no
assurance that required approvals will be obtained. If we were unable to obtain
these approvals on a timely basis or at all, our ability to successfully market
products directly and through our collaborators, and to generate revenues from
sales or royalties, would be impaired.

All approved products are subject to continuing regulation. If we were
to fail to comply with applicable requirements, we could be subject to:

o fines, recall or seizure of products;

o total or partial suspension of production;

o refusal by the government to approve our product license
applications;

o restrictions on our ability to enter into supply contracts; and

o criminal prosecution.

The FDA also has the authority to revoke product licenses and
establishment licenses previously granted to us. Currently, we are marketing
Ethyol for the treatment of patients with NSCLC. This indication was approved
under the FDA's Accelerated Approval Regulations. These regulations require that
we conduct clinical studies to verify and describe the clinical benefit of the
approved indication.

We have completed trials which we anticipate will be sufficient to meet
the FDA's requirements. If the FDA is not satisfied that we have met the
requirements, it may withdraw its approval of Ethyol in the NSCLC indication.
Should the FDA revoke any product or establishment licenses granted to us, it
could have a material adverse effect on our business.

PRODUCT LIABILITY CLAIMS MAY RESULT FROM SALES OF OUR PRODUCTS AND PRODUCT
RECALLS MAY BE NECESSARY.

As a developer, tester, manufacturer, marketer and seller of healthcare
products, we are potentially subject to product liability claims. Our blood
products, such as CytoGam and RespiGam, involve heightened risks of claims,
including the risk of claims resulting from the transmission of blood-borne
diseases. Defending a product liability claim could be costly and divert our
focus from business operations. Although we carry insurance that we regard as
reasonably adequate to protect us from potential claims, there can be no
assurance that we will be able to maintain our current product liability
insurance at a reasonable cost, or at all. If a claim were successful, there is
no guarantee that the amount of the claim would not exceed the limit of our
insurance coverage. Further, a successful claim could result in the recall of
some or all of our products. Any of these occurrences could have a material
adverse effect on our business. Additionally, blood products like CytoGam and
RespiGam are occasionally recalled from the market because of risks of
contamination from infectious agents or for other reasons which are often beyond
our control. Any such recall of our blood products would adversely affect our
sales.

THE LOSS OF KEY PERSONNEL COULD HARM OUR BUSINESS.

Our success depends upon the continued contributions of our executive
officers and scientific and technical personnel. Many key responsibilities have
been assigned to a relatively small number of individuals. Our key personnel
include Mr. David M. Mott, Chief Executive Officer and Vice Chairman of the
Board; Mr. Melvin D. Booth, President and Chief Operating Officer; and Dr. James
F. Young, President, Research and Development. We have an employment agreement
with each of them. The competition for qualified personnel is intense, and the
loss of services or certain key personnel could adversely affect our business.
We do not maintain or intend to purchase "key man" life insurance on any of our
personnel.

FLUCTUATIONS IN OUR COMMON STOCK PRICE OVER TIME COULD CAUSE OUR STOCKHOLDERS TO
LOSE INVESTMENT VALUE.

The market price of our common stock has fluctuated significantly over
time, and it is likely that the price will fluctuate in the future. During 2001,
the closing price of our common stock on the Nasdaq stock market ranged from a
high of $52.36 to a low of $28.31. Investors and analysts have been, and will
continue to be, interested in our reported earnings, as well as how we perform
compared to their expectations. Announcements by us or others regarding
operating results, existing and future collaborations, results of clinical
trials, scientific discoveries, commercial products, patents or proprietary
rights or regulatory actions may have a significant effect on the market price
of our common stock. In addition, the stock market has experienced extreme price
and volume fluctuations that have particularly affected the market price for
many biotechnology companies and that have often been unrelated to the operating
performance of these companies. These broad market fluctuations may adversely
affect the market price of our common stock.

CHANGES IN FOREIGN CURRENCY EXCHANGE RATES OR INTEREST RATES COULD RESULT IN
LOSSES.

We have entered into foreign exchange forward contracts which could
result in losses. Because we have contracts for the future purchase of inventory
which are denominated in foreign currencies, there is a chance that foreign
currency exchange rate or interest rate changes could result in increases or
decreases in the actual cost of our purchases. To reduce the risk of
unpredictable changes in the cost of our purchases, we may enter into forward
foreign exchange contracts, which allow us to purchase, for a fixed price on a
specific date in the future, the amount of foreign currency necessary to pay for
our

contractual purchase of inventory. Fluctuations in the anticipated payment date
for the inventory could require us to adjust the date of the contract, which
could result in a change in the foreign currency exchange rate of the contracts,
which in turn could have an adverse effect on our financial results.

Expenditures relating to our manufacturing operations in the United
Kingdom and the Netherlands are paid in local currency. We have not hedged our
expenditures relating to these manufacturing operations, and therefore foreign
currency exchange rate fluctuations may result in increases or decreases in the
amount of expenditures recorded. Additionally, certain of our distribution
agreements outside the United States provide for us to be paid based upon sales
in local currency. As a result, changes in foreign currency exchange rates could
adversely affect the amount we expect to collect under these agreements.

THE SUCCESS OF OUR PRODUCTS MAY BE LIMITED BY GOVERNMENT AND THIRD-PARTY PAYORS.

The continuing efforts of government and third-party payors to contain
or reduce the costs of health care through various means may negatively affect
sales of our products. For example, approximately 24% of all Synagis vials sold
in the United States during the 2000-2001 RSV season were covered by Medicaid
reimbursement programs. In many foreign markets, pricing and profitability of
pharmaceutical products is subject to governmental control. In the United States
there have been, and we expect there will continue to be, various federal and
state proposals to implement similar government controls over pricing and
profitability. The adoption by the federal government or state governments of
any such proposals could limit the commercial success of our existing or any
future products.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus contains or incorporates certain forward-looking
statements within the meaning of the Private Securities Litigation Reform Act of
1995. Statements that are not historical facts are hereby identified as
"forward-looking statements" for the purpose of the safe harbor provided by
Section 21E of the Exchange Act and Section 27A of the Securities Act. Such
forward-looking statements, including, without limitation, those relating to the
future business prospects, revenues and income of MedImmune, wherever they occur
in this prospectus, are necessarily estimates reflecting and involve a number of
risks and uncertainties that could cause actual results to differ materially
from those suggested by the forward-looking statements. Such forward-looking
statements should, therefore, be considered in light of various important
factors, including those set forth in this prospectus. Important factors that
could cause actual results to differ materially from estimates or projections
contained in the forward-looking statements include without limitation:

-- challenges inherent in new product development and marketing

-- failure to get approval for or successfully commercialize potential
products

-- governmental laws and regulations, including possible healthcare
reform

-- competitive factors, including technological advances achieved and
patents attained by competitors and generic competition as patents
on MedImmune's products expire

-- government laws and regulations affecting domestic and foreign
operations, including those relating to trade, monetary and fiscal
policies, taxes, price controls, regulatory approval of new products
and licensing

-- those factors listed in MedImmune's reports and filings with the
U.S. Securities and Exchange Commission.

Words such as "estimate," "project," "plan," "intend," "expect,"
"believe" and similar expressions are intended to identify forward-looking
statements. These forward-looking statements are found, among other places, in
the documents incorporated by reference, including, but not limited to,
MedImmune's Annual Report on Form 10-K for the year ended December 31, 2001,
including any amendments. Readers are cautioned not to place undue reliance on
these forward-looking statements, which speak only as of the date of this
prospectus. MedImmune undertakes no obligation to publicly update or release any
revisions to these forward-looking statements to reflect events or circumstances
after the date of this prospectus or to reflect the occurrence of unanticipated
events.

The foregoing list sets forth some, but not all, of the factors that
could affect MedImmune's ability to achieve results described in any
forward-looking statements. Investors are cautioned not to place undue reliance
on such statements that speak only as of the date made. Investors also should
understand that it is not possible to predict or identify all such factors and
that this list should not be considered a complete statement of all potential
risks and uncertainties. Investors should also realize that if underlying
assumptions prove inaccurate or unknown risks or uncertainties materialize,
actual results could vary materially from MedImmune's projections. MedImmune
undertakes no obligation to update any forward-looking statements as a result of
future events or developments.

MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES

The following is a general discussion of the material U.S. federal
income tax consequences of converting the convertible notes into MedImmune stock
and of acquiring MedImmune stock pursuant to the warrants. This discussion does
not address any other tax consequences, including, without limitation, any tax
consequences to holders of convertible notes or warrants of any past, current or
future adjustments to, or changes in, the conversion or exercise terms of the
convertible notes or warrants (including, without limitation, adjustments to, or
changes in, the conversion or exercise price or the consideration received upon
conversion or exercise, whether arising out of consummation of MedImmune's
acquisition of Aviron or otherwise).

This discussion is based on currently existing provisions of the
Internal Revenue Code of 1986, as amended (the "Code"), Treasury regulations
promulgated thereunder, and administrative and judicial interpretations thereof,
all as in effect on the date hereof and all of which are subject to change,
possibly on a retroactive basis. Moreover, this discussion is for general
information only and does not address all of the U.S. federal income tax
consequences that may be relevant to particular holders in light of their
personal circumstances. In addition, this discussion does not address the U.S.
federal income tax consequences that may be applicable to certain types of
holders, including, for example, foreign persons or entities, banks and other
financial institutions, insurance companies, tax-exempt entities, dealers in
securities, partnerships and other pass-through entities, persons holding the
convertible notes or warrants as part of a hedging or conversion transaction, an
appreciated financial position or a straddle, holders that have a functional
currency other than the U.S. dollar, or holders that do not hold their
convertible notes or warrants as capital assets. This discussion does not
include any description of the tax laws of any state, local, or foreign
government that may be applicable to a particular holder.

THIS DISCUSSION OF MATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS IS
FOR GENERAL INFORMATION ONLY. IT IS NOT TAX ADVICE. HOLDERS ARE URGED TO CONSULT
THEIR OWN TAX ADVISORS AS TO THE PARTICULAR U.S. FEDERAL INCOME AND OTHER TAX
CONSEQUENCES TO THEM OF THE CONVERSION OF CONVERTIBLE NOTES OR THE EXERCISE OF
WARRANTS, AS WELL AS THE TAX CONSEQUENCES UNDER STATE, LOCAL, AND FOREIGN TAX
LAWS, AND THE POSSIBLE EFFECTS OF CHANGES IN TAX LAWS. IN ADDITION, HOLDERS ARE
URGED TO CONSULT THEIR OWN TAX ADVISORS AS TO ANY OTHER TAX CONSEQUENCES
RELATING TO THEIR ACQUISITION, OWNERSHIP OR DISPOSITION OF THE CONVERTIBLE NOTES
OR WARRANTS.

CONVERSION OF THE CONVERTIBLE NOTES

Subject to the market discount rules discussed below, a holder
generally will recognize capital gain or loss upon the conversion of a
convertible note into MedImmune stock in an amount equal to the difference
between (i) the fair market value of the stock plus cash in lieu of fractional
shares received upon the conversion and (ii) the holder's adjusted tax basis in
the convertible note at the time of conversion. Such capital gain or loss
generally will be long-term capital gain or loss if the holder held the
convertible note for more than one year at the time of conversion. The
deductibility of capital losses is subject to limitations.

If the holder's convertible note has "market discount," any gain
recognized on the conversion of the convertible note into MedImmune stock will
be treated as ordinary income rather than capital gain to the extent of the
accrued "market discount" on the date of conversion, unless an election was made
to include "market discount" in income as it accrued. "Market discount" is
includible in income only to the extent of the realized gain on the conversion
of the convertible note. In general, and subject to a de minimis exception, the
"market discount" on a convertible note will equal the amount, if any, by which
the stated redemption price at maturity of the note exceeds the holder's
adjusted tax basis in the convertible note. Market discount will be treated as
accruing ratably over the period from the date of the

holder's acquisition of the convertible note to the maturity date of the
convertible note or, at the election of the holder, on a constant interest rate
basis.

Generally, the holder's tax basis in the MedImmune stock received in
the conversion will be the fair market value of such stock, and the holding
period of such stock will begin on the day following the date of conversion.

EXERCISE OF THE WARRANTS

The U.S. federal income tax consequences of exercise of the warrants is
unclear and may depend on, among other things, the tax treatment of the warrants
at the time of issuance, the means of exercising the warrants and /or the
identity of the holder of the warrants. Depending on the particular facts and
the resolution of certain issues, the exercise of the warrants could be treated
as a fully taxable transaction with the holder of the warrants recognizing
income, gain or loss in an amount equal to the difference between (i) the fair
market value of the MedImmune stock plus cash in lieu of fractional shares
received upon exercise and (ii) the amount paid, if any, to exercise the
warrants plus the holder's basis in the warrants at the time of exercise.
Alternatively, the exercise of the warrants could be treated as a non-taxable
transaction in which no income, gain or loss is recognized by the holder of the
warrants other than with respect to cash received in lieu of fractional shares.
Other characterizations may also be possible. Holders of warrants are urged to
consult their tax advisors regarding the tax consequences of exercise of the
warrants, including the recognition of income, gain or loss, the holder's basis
and holding period in the MedImmune stock acquired and the impact on the
foregoing of the tax treatment of the warrants at the time of issuance, the
means of exercising the warrants and/or the identity of the holder.

BACKUP WITHHOLDING AND INFORMATION REPORTING

Under the Code, a holder may be subject to backup withholding with
respect to cash received in lieu of a fractional share upon conversion of a
convertible note or exercise of a warrant unless the holder provides proof of an
applicable exemption or a correct taxpayer identification number. In addition,
the receipt of cash in lieu of a fractional share by holders other than certain
exempt recipients may be subject to information reporting requirements.

USE OF PROCEEDS

Assuming the warrants are exercised in full for cash, MedImmune
Vaccines will receive aggregate proceeds in the amount of approximately
$3,900,000. Any proceeds to MedImmune Vaccines from the issuance of any
shares will be used for general business purposes. We will not receive
any proceeds from the conversion of convertible notes, as all proceeds
relating to the convertible notes were received by MedImmune Vaccines at the
time the convertible notes were originally issued. We will pay all expenses
with respect to this offering.

PLAN OF DISTRIBUTION

The shares of MedImmune stock offered by this prospectus are issuable
upon exercise of the warrants or upon conversion of the convertible notes. Set
forth below is a summary of selected terms of the warrants and convertible notes
relevant to exercise or conversion.

Terms of the Warrants

In January 2002, MedImmune acquired Aviron, which has been renamed
MedImmune Vaccines, Inc., by means of a merger (the "merger") of a subsidiary
of MedImmune into Aviron. The following description of selected terms of the
warrants gives effect to the merger. This description does not purport to be
complete and is qualified in its entirety by reference to the terms of the
warrants, copies of which are exhibits to the registration statement of which
this prospectus is a part. We urge you to read the warrants because the
warrants, and not this description, define your rights as holders of the
warrants, including your right to exercise the warrants.

GENERAL. The warrants were originally issued by Aviron prior to the
date of the merger and have been replaced by replacement warrants issued by
Aviron to reflect the adjustments described below. Prior to the merger, the
warrants represented the right, exercisable during the exercise period specified
with respect to the warrants, to purchase shares of Aviron common stock. As a
result of the merger, each warrant became exercisable for shares of MedImmune
stock as described below in accordance with the terms of the warrants.

EXERCISE. The warrants provide that the warrants may be exercised in
whole or in part at any time or from time to time during the exercise period
specified for the warrants. After the merger, a warrant may be exercised by
delivery of the warrants to MedImmune Vaccines, with the purchase or exercise
form attached to the warrant duly executed and accompanied by cash or a
certified or official bank check or wire transfer in the amount of the
exercise price per share multiplied by the number of shares specified in the
form. The exercise price may also be paid by tendering warrants having a net
issuance value equal to the exercise price. If any warrant is exercised in
part only, MedImmune Vaccines will, upon delivery of the original warrant,
execute and deliver a new warrant evidencing the right to purchase the
balance of the shares of MedImmune stock purchasable under the warrant.

ADJUSTMENT OF WARRANTS. Under the terms of the warrants, as of the
effective date of the merger, each outstanding and unexercised warrant that
prior to the merger represented a right to acquire shares of Aviron common stock
was converted into a right to acquire 1.075 shares of MedImmune stock for each
share of Aviron common stock that the warrant was exercisable for immediately
prior to the merger. This number was determined based on the exchange ratio in
the merger that was used to convert outstanding Aviron common stock into
MedImmune stock.

The respective exercise prices and the numbers of shares issuable upon
exercise of the warrants are subject to further adjustment upon the occurrence
of stock dividends, splits, combinations and various other events affecting the
MedImmune stock.

EXERCISE PRICES, EXPIRATION OF WARRANTS. As a result of the merger, the
warrants have become exercisable for shares of MedImmune stock and the exercise
price of the warrants has been adjusted based on the exchange ratio in the
merger. Prior to the merger, the warrants were exercisable for a total of
390,000 Aviron shares at an exercise price of $10.00 per share. As a result of
the merger, the warrants are exercisable for a total of 419,250 MedImmune shares
at an exercise price of approximately $9.30 per share. On February 15, 2007,
340,000 warrants will expire and on March 28, 2008, 50,000 warrants will expire.

NO RIGHTS AS STOCKHOLDERS. The warrants do not entitle the warrant holders
to any voting rights or other rights as stockholders of MedImmune.

TERMS OF THE CONVERTIBLE NOTES

The following description of selected terms of the convertible notes
gives effect to the merger. This description does not purport to be complete and
is qualified in its entirety by reference to the terms of the convertible notes
and the related indenture and supplemental indenture, copies of which are
exhibits to the registration statement of which this prospectus is a part. We
urge you to read the indenture and supplemental indenture governing the notes
because those documents, and not this description, define your rights as holders
of the notes, including your right to convert the notes into shares of MedImmune
stock.

GENERAL. The convertible notes were issued by Aviron prior to the date
of the merger under an Indenture, dated as of February 7, 2001, as supplemented
by an Officer's Certificate, dated as of February 7, 2001 and a Supplemental
Indenture, dated as of January 15, 2002, in each case between Aviron and HSBC
Bank USA, as trustee. Prior to the merger, the convertible notes were
convertible at the option of the holders of the convertible notes into shares of
Aviron common stock. As a result of the merger, each convertible note became
convertible into shares of MedImmune stock as described below in accordance with
the terms of the convertible notes, the indenture, the supplemental indenture.

CONVERSION. The indenture and supplemental indenture provide that in
order to convert a convertible note, the holder must (i) execute and deliver the
conversion notice for the convertible note to MedImmune Vaccines and the
trustee, (ii) surrender the convertible note to MedImmune Vaccines and (iii)
furnish appropriate endorsements and transfer documents.

ADJUSTMENT OF CONVERSION TERMS. Under the terms of the convertible
notes, the indenture and the supplemental indenture, as of the effective date of
the merger, each outstanding convertible note that prior to the merger was
convertible into Aviron shares became convertible into MedImmune shares.

The conversion price of the convertible notes prior to the merger was
$62.50. As a result of the merger, the conversion price of the convertible notes
was adjusted to $62.50 divided by 1.075, and the convertible notes are now
convertible into a total of 3,440,000 MedImmune shares. This number was
determined based on the exchange ratio in the merger that was used to convert
outstanding Aviron common stock into MedImmune stock.

The conversion price of the convertible notes is subject to further
adjustment upon the occurrence of stock dividends, splits, combinations and
various other events affecting the MedImmune stock.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and special reports, proxy statements and
other information with the SEC under the Exchange Act. You may read and copy
this information at the Public Reference Room of

the SEC, 450 Fifth Street, N.W., Room 1024, Washington, D.C. 20549. Please call
the SEC at 1-800-SEC-0330 for further information.

You may also obtain copies of this information by mail from the Public
Reference Section of the SEC, 450 Fifth Street, N.W., Room 1024, Washington,
D.C. 20549, at prescribed rates.

The SEC also maintains an Internet web site that contains reports,
proxy statements and other information about issuers, like MedImmune, who file
electronically with the SEC. The address of that site is http://www.sec.gov.

You can also inspect reports, proxy statements and other information
about MedImmune at the offices of the Nasdaq National Market, 20 Broad Street,
New York, New York 10005.

We filed a registration statement on Form S-3 to register with the SEC
the sale of the shares of MedImmune common stock to be issued pursuant to the
warrants and convertible notes. This prospectus is a part of that registration
statement. As allowed by SEC rules, this prospectus does not contain all the
information you can find in the registration statement or the exhibits to the
registration statement. You may obtain copies of the Form S-3 (and any
amendments) in the manner described above.

The SEC allows us to "incorporate by reference" information into this
prospectus, which means that we can disclose important information to you by
referring you to another document filed separately with the SEC. The information
incorporated by reference is deemed to be part of this prospectus, except for
any information superseded by information contained directly in this prospectus.
This prospectus incorporates by reference the documents set forth below that we
have previously filed with the SEC. These documents contain important
information about us and our financial condition.

The following documents listed below that we have previously filed with
the SEC are incorporated by reference:

MEDIMMUNE SEC FILINGS

Quarterly Report on Form 10-Q...................... Quarter ended March 31, 2002
Quarter ended June 30, 2002
Annual Report on Form 10-K......................... Year ended December 31, 2001
Current Report on Form 8-K......................... Dated January 16, 2002
Dated January 10, 2002
Dated July 10, 2002
Dated August 16, 2002
Description of Common Stock and Amended and
Restated Rights Agreement.......................... Incorporated by reference to MedImmune's Registration
Statements on Form 8-A dated April 4, 1991 and
December 1, 1998
Selected Unaudited Pro Forma Condensed Combined
Financial Data of MedImmune and Aviron............. Incorporated by reference to MedImmune's Current
Report on Form 8-K filed July 10, 2002
16

We also incorporate by reference the documents any future filings we
make with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Securities
Exchange Act of 1934 until the end of the offering of MedImmune common stock
made under this prospectus.

Any person receiving a copy of this prospectus may obtain, without
charge, upon written or oral request, a copy of any of the documents
incorporated by reference in this prospectus, excluding all exhibits unless we
have specifically incorporated by reference an exhibit in this prospectus.
Written requests should be directed to MedImmune, Inc., 35 West Watkins Mill
Road, Gaithersburg, Maryland 20878 (telephone number (301) 417-0770), Attention:
Corporate Secretary.

LEGAL OPINIONS

The validity of the shares of MedImmune common stock will be passed
upon for MedImmune by Dewey Ballantine LLP, New York, New York.

EXPERTS

The financial statements incorporated in this prospectus by reference
to MedImmune, Inc.'s Annual Report on Form 10-K for the year ended December 31,
2001 have been so incorporated in reliance on the report of
PricewaterhouseCoopers LLP, independent accountants, given on the authority of
said firm as experts in accounting and auditing.

The consolidated financial statements of Aviron for the year ended
December 31, 2001 incorporated in this prospectus by reference to the Current
Report on Form 8-K of MedImmune, Inc. dated July 10, 2002 have been so
incorporated in reliance on the report of PricewaterhouseCoopers LLP,
independent accountants, given on the authority of said firm as experts in
auditing and accounting.

The consolidated financial statements of Aviron at December 31, 2000
and for each of the two years in the period ended December 31, 2000,
appearing in our Current Report on Form 8-K dated July 10, 2002 have been
audited by Ernst & Young LLP, independent auditors, as set forth in their
report thereon included therein and incorporated herein by reference. Such
consolidated financial statements are incorporated herein by reference in
reliance upon such report given on the authority of such firm as experts in
accounting and auditing.

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION.

The estimated expenses payable by MedImmune in connection with this
offering are as follows:

Securities and Exchange Commission registration fee................... $12,420

Stock exchange listing fee............................................ 3,860

Accounting fees and expenses.......................................... 18,500

Printing expenses..................................................... 10,000

Legal fees and expenses............................................... 25,000
------
Total........................................................ $69,780

ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

Subsection (a) of Section 145 of the General Corporation Law of the
State of Delaware (the "DGCL") empowers a corporation to indemnify any person
who was or is a party or who is threatened to be made a party to any threatened,
pending or completed action, suit or proceeding, whether civil, criminal,
administrative or investigative (other than an action by or in the right of the
corporation) by reason of the fact that the person is or was a director,
officer, employee or agent of the corporation, or is or was serving at the
request of the corporation as a director, officer, employee or agent of another
corporation, partnership, joint venture, trust or other enterprise, against
expenses (including attorney's fees), judgments, fines and amounts paid in
settlement actually and reasonably incurred by the person in connection with
such action, suit or proceeding if the person acted in good faith and in a
manner the person reasonably believed to be in or not opposed to the best
interests of the corporation, and, with respect to any criminal action or
proceeding, had no reasonable cause to believe the person's conduct was
unlawful.

Subsection (b) of Section 145 empowers a corporation to indemnify any
person who was or is a party or is threatened to be made a party to any
threatened, pending or completed action or suit by or in the right of the
corporation to procure a judgment in its favor by reason of the fact that the
person acted in any of the capacities set forth above, against expenses
(including attorney's fees) actually and reasonably incurred by him in
connection with the defense or settlement of such action or suit if the person
acted in good faith and in a manner the person reasonably believed to be in or
not opposed to the best interests of the corporation, except that no
indemnification shall be made in respect of any claim, issue or matter as to
which such person shall have been adjudged to be liable to the corporation
unless and only to the extent that the Court of Chancery or the court in which
such action or suit was brought shall determine upon application that, despite
the adjudication of liability but in view of all the circumstances of the case,
such person is fairly and reasonably entitled to indemnity for such expenses
which the Court of Chancery or such other court shall deem proper.

Section 145 further provides that to the extent a director or officer
of a corporation has been successful on the merits or otherwise in the defense
of any action, suit or proceeding referred to in subsections (a) and (b) of
Section 145, or in defense of any claim, issue or matter therein, he shall be

II-1

indemnified against expenses (including attorneys' fees) actually and reasonably
incurred by him in connection therewith; that indemnification provided for by
Section 145 shall not be deemed exclusive of any other rights to which the
indemnified party may be entitled; the indemnification provided for by Section
145 shall, unless otherwise provided when authorized or ratified, continue as to
a person who has ceased to be a director, officer, employee or agent and shall
inure to the benefit of such person's heirs, executors and administrators; and
empowers the corporation to purchase and maintain insurance on behalf of any
person who is or was a director, officer, employee or agent of the corporation,
or is or was serving at the request of the corporation as a director, officer,
employee or agent of another corporation, partnership, joint venture, trust or
other enterprise against any liability asserted against him and incurred by him
in any such capacity, or arising out of his status as such, whether or not the
corporation would have the power to indemnify him against such liabilities under
Section 145.

MedImmune provides liability insurance for its directors and officers
which provides for coverage against loss from claims made against directors and
officers in their capacity as such, including liabilities under Securities Act
of 1933.

Section 102(b)(7) of the DGCL provides that a certificate of
incorporation may contain a provision eliminating or limiting the personal
liability of a director to the corporation of its stockholders for monetary
damages for breach of fiduciary duty as a director, provided that such provision
shall not eliminate or limit the liability of a director (i) for any breach of
the director's duty of loyalty to the corporation or its stockholders, (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the DGCL, or (iv) for a
transaction from which the director derived an improper personal benefit.
Article EIGHTH of MedImmune's Certificate of Incorporation limits the liability
of directors to the fullest extent permitted by Section 102(b)(7).

ITEM 16. EXHIBITS.

3.1 Amended Restated Certificate of Incorporation of MedImmune, Inc.
(incorporated by reference to Exhibits 3.1, 3.4, 3.5 and 3.6 to MedImmune,
Inc.'s Annual Report on Form 10-K for the year ended December 31, 2001).

3.2 Bylaws of MedImmune, Inc. (incorporated by reference to Exhibit 3.7 to
MedImmune, Inc.'s Annual Report on Form 10-K for the year ended December
31, 2001).

4.1 Amended and Restated Rights Agreement, dated as of October 31, 1998,
between MedImmune, Inc., and American Stock Transfer and Trust Company, as
Rights Agent (incorporated by reference to Exhibit 99.2 in MedImmune
Inc.'s Registration Statement on Form 8A/A (Commission File No.
001-14657)).

4.2 Form of Warrant for Common Stock, issued to the University of Michigan.**

4.3 Form of Warrant for Common Stock, issued to the University of Michigan.**

4.4 Indenture entered into between Aviron and HSBC Bank USA as Trustee, dated
February 7, 2001 (incorporated by reference to Exhibit 4.22 in Aviron's
Annual Report on Form 10-K for the year ended December 31, 2000).

4.5 Officer's Certificate pursuant to Section 2.01 of the Subordinated
Indenture, dated February 7, 2001 (incorporated by reference to Exhibit
4.23 in Aviron's Annual Report on Form 10-K for the year ended
December 31, 2000).

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4.6 Supplemental Indenture among Aviron, MedImmune, Inc. and HSBC Bank USA as
Trustee, dated January 15, 2002.**

5.1 Opinion of Dewey Ballantine LLP.**

23.1 Consent of PricewaterhouseCoopers LLP.*

23.2 Consent of Ernst & Young LLP, Independent Auditors.*

23.4 Consent of Dewey Ballantine LLP (contained in Exhibit 5.1).

24.1 Powers of Attorney (included on the signature page hereto).
------------------------------------------
* Filed herewith

** Previously filed

------------------------------------------

ITEM 17. UNDERTAKINGS.

(a) The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made,
a post-effective amendment to this registration statement;

(i) To include any prospectus required by Section 10(a)(3)
of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising
after the effective date of the registration statement (or the most
recent post-effective amendment thereof) which, individually or in the
aggregate, represent a fundamental change in the information set forth
in the registration statement. Notwithstanding the foregoing, any
increase or decrease in the volume of securities offered (if the total
dollar value of securities offered would not exceed that which was
registered) and any deviation from the low or high and of the estimated
maximum offering range may be reflected in the form of prospectus filed
with the Commission pursuant to Rule 424(b) if, in the aggregate, the
changes in volume and price represent no more than 20 percent change in
the maximum aggregate offering price set forth in the "Calculation of
Registration Fee" table in the effective registration statement;

(iii) To include any material information with respect to the
plan of distribution not previously disclosed in the registration
statement or any material change to such information in the
registration statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the
registration statement is on Form S-3, Form S-8 or Form F-3, and the information
required to be included in a post-effective amendment by those paragraphs is
contained in periodic reports filed with or furnished to the Commission by the
registrant pursuant to Section 13 or 15(d) of the Securities Exchange Act of
1934 that are incorporated in the registration statement.

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(2) That, for the purpose of determining any liability under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

(3) To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering.

(b) The undersigned registrant hereby undertakes that, for
purposes of determining any liability under the Securities Act of 1933, each
filing of the registrant's annual report pursuant to Section 13(a) or Section
15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing
of an employee benefit plan's annual report pursuant to Section 15(d) of the
Securities Exchange Act of 1934) that is incorporated by reference in the
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.

(c) Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the registrant pursuant to the foregoing provisions, or otherwise,
the registrant has been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.

(d) The undersigned registrant hereby undertakes that:

(1) For purposes of determining any liability under the Securities Act
of 1933, the information omitted from the form of prospectus filed as part of
this registration statement in reliance upon Rule 430A and contained in a form
of prospectus filed by the registrant pursuant to Rule 424(b)(1) or (4) or
497(h) under the Securities Act shall be deemed to be part of this registration
statement as of the time it was declared effective.

(2) For the purpose of determining any liability under the Securities
Act of 1933, each post-effective amendment that contains a form of prospectus
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the
Registrant has duly caused this amendment to the Registration Statement on Form
S-3 to be signed on its behalf by the undersigned, thereunto duly authorized, in
the City of Gaithersburg, State of Maryland, on September 5, 2002.

MedImmune, Inc.

By: /s/ David M. Mott
Name: David M. Mott
Title: Chief Executive Officer and Vice
Chairman of the Board

Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities and on the dates indicated.

SIGNATURE TITLE DATE
--------- ----- ----

* Chairman of the Board and the September 5, 2002
----------------------------------------------------- Executive Committee
Wayne T. Hockmeyer, Ph.D.

/s/ David M. Mott Chief Executive Officer and Vice September 5, 2002
----------------------------------------------------- Chairman of the Board (Principal
David M. Mott Executive Officer)

* President, Chief Operating Officer September 5, 2002
----------------------------------------------------- and Director
Melvin D. Booth

* Senior Vice President and Chief September 5, 2002
----------------------------------------------------- Financial Officer (Principal
Gregory S. Patrick Financial Officer and Principal
Accounting Officer)

* Executive Vice President, Medical September 5, 2002
----------------------------------------------------- Director and Director
Franklin H. Top, Jr., M.D.

* Director September 5, 2002
-----------------------------------------------------
M. James Barrett, Ph.D.

* Director September 5, 2002
-----------------------------------------------------
James H. Cavanaugh, Ph.D.

* Director September 5, 2002
-----------------------------------------------------
Barbara Hackman Franklin

* Director September 5, 2002
-----------------------------------------------------
Gordon S. Macklin

*By: /s/ David M. Mott
-----------------
David M. Mott, ATTORNEY-IN-FACT

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EXHIBIT INDEX

Exhibit
Number Description
------ -----------

3.2 Bylaws of MedImmune, Inc. (incorporated by reference to Exhibit 3.7 to
MedImmune, Inc.'s Annual Report on Form 10-K for the year ended December
31, 2001).

4.2 Form of Warrant for Common Stock, issued to the University of Michigan.**

4.3 Form of Warrant for Common Stock, issued to the University of Michigan.**

4.6 Supplemental Indenture among Aviron, MedImmune, Inc. and HSBC Bank USA as
Trustee, dated January 15, 2002.**

5.1 Opinion of Dewey Ballantine LLP.**

23.1 Consent of PricewaterhouseCoopers LLP.*

23.2 Consent of Ernst & Young LLP, Independent Auditors.*

23.4 Consent of Dewey Ballantine LLP (contained in Exhibit 5.1).

24.1 Powers of Attorney (included on the signature page hereto).

------------------------------------------
* Filed herewith

**Previously filed

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