Press release Sanofi Pasteur


Swiftwater, Pennsylvania and Lyon, France, April 28, 2008




U.S. Government accepts $192 million
of Sanofi Pasteur H5N1 bulk vaccine
antigen for pandemic stockpile

- Vaccine for new strain of virus broadens
government readiness program -

Sanofi Pasteur, the vaccines division of sanofi-aventis Group, announced today that the U.S.
Department of Health and Human Services (HHS) has accepted H5N1 bulk vaccine antigen to
produce approximately 38.5 million doses of vaccine to protect against a new strain of avian
influenza. Sanofi Pasteur has a multi-year contract with HHS as part of its pandemic program, and
will receive a payment of $192.5 million booked in the second quarter of 2008 for acceptance of the
bulk vaccine lot. In 2007, sanofi pasteur received $126.9 million for its bulk pandemic vaccine.

The dose calculation is based on antigen concentration of seasonal influenza vaccine, which
contains 15 mcg per dose. When the dose calculation is based on concentration of sanofi pasteur’s
licensed pandemic vaccine, which contains 90 mcg per dose, bulk antigen will yeld 6.4 million
i
doses. Since the vaccine is supplied to the government in bulk concentrate form, final formulation
will not occur until the vaccine is needed. At that time, the actual number of doses will be
determined.

This acceptance represents the U.S. government’s latest effort to diversify the vaccine stockpile
program to include new strains of the H5N1 virus. The antigen lot accepted today will protect
against a clade 2.2 strain of H5N1 virus (A/Barheaded goose/Qinghai Lake/01/2005) that is
particularly troubling because it is the first to be identified in an outbreak of migratory birds, which
have the potential to spread the virus across continents. This strain of avian influenza H5N1 virus is
the strain that currently predominates in birds of Europe, the Middle East, and Africa.

The bulk antigen was produced at sanofi pasteur’s U.S. site in Swiftwater, PA. As the world leader
in research, development and manufacturing of influenza vaccine, sanofi pasteur is actively
involved in projects in the U.S. and Europe with the goal of developing a vaccine to protect against
a pandemic influenza virus.

In June 2007, sanofi pasteur completed construction of a new manufacturing facility that is
expected to more than double its capacity to produce both seasonal and pandemic influenza when
it begins production in early 2009. Sanofi Pasteur leads the way in pandemic preparedness with the
first and only U.S. licensed avian influenza vaccine for humans and has successfully achieved




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manufacturing scale-up of this first generation vaccine using proven, licensed and existing
technology.


About Pandemic Influenza
An influenza pandemic is a global epidemic of an especially virulent virus, newly infectious for
humans, and for which there is no preexisting immunity. This is why pandemic strains have such
potential to cause severe morbidity and mortality. The H5N1 viral strain has been identified by
global health authorities as being a potential cause of a pandemic. In an attempt to minimize the
impact of a pandemic, many countries are developing national and transnational plans against a
possible influenza pandemic situation. According to the World Health Organization (WHO), there
have been 381 cases of avian influenza transmitted to humans since 2003, with 240 resulting in
death.

Sanofi Pasteur and Pandemic Preparedness
Sanofi Pasteur is committed to global pandemic preparedness. Sanofi Pasteur is investing in major
expansions of its seasonal influenza vaccine production facilities in the U.S. and France, which
could be used to produce pandemic influenza vaccine if the need arises. For more information
please visit http://pandemic.influenza.com

About sanofi-aventis
Sanofi-aventis, a leading global pharmaceutical company, discovers, develops and distributes
therapeutic solutions to improve the lives of everyone. Sanofi-aventis is listed in Paris (EURONEXT
PARIS: SAN) and in New York (NYSE: SNY);

Sanofi Pasteur, the vaccines division of sanofi-aventis Group, provided more than a 1.6 billion
doses of vaccine in 2007, making it possible to immunize more than 500 million people across the
globe. A world leader in the vaccine industry, sanofi pasteur offers the broadest range of vaccines
protecting against 20 infectious diseases. The company's heritage, to create vaccines that protect
life, dates back more than a century. Sanofi Pasteur is the largest company entirely dedicated to
vaccines. Every day, the company invests more than EUR1 million in research and development.
For more information, please visit: www.sanofipasteur.com or www.sanofipasteur.us

Forward Looking Statements
This press release contains forward-looking statements as defined in the Private Securities Litigation Reform
Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. These
statements include financial projections and estimates and their underlying assumptions, statements
regarding plans, objectives, intentions and expectations with respect to future events, operations, products
and services, and statements regarding future performance. Forward-looking statements are generally
identified by the words “expects,” “anticipates,” “believes,” “intends,” “estimates,” “plans” and similar
expressions. Although sanofi-aventis’ management believes that the expectations reflected in such forward-
looking statements are reasonable, investors are cautioned that forward-looking information and statements
are subject to various risks and uncertainties, many of which are difficult to predict and generally beyond the
control of sanofi-aventis, that could cause actual results and developments to differ materially from those
expressed in, or implied or projected by, the forward-look ing information and statements. These risks and
uncertainties include those discussed or identified in the public filings with the SEC and the AMF made by
sanofi-aventis, including those listed under “Risk Factors” and “Cautionary Statement Regarding Forward-
Looking Statements” in sanofi-aventis’ annual report on Form 20-F for the year ended December 31,
2007. Other than as required by applicable law, sanofi-aventis does not undertake any obligation to update or
revise any forward-looking information or statements.



Global Media Relations US Media Relations
Pascal Barollier Len Lavenda
T. +33-(0)4-37-37-50-38 T. +1-570-839-4446
pascal.barollier@sanofipasteur.com len.lavenda@sanofipasteur.com
www.sanofipasteur.com www.sanofipasteur.us




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