Sanofi Pasteur Presents Positive Results of Tetravalent Dengue Candidate Vaccine

Lyon, France, November 6 (ots/PRNewswire) - Sanofi Pasteur, the
vaccines division of sanofi-aventis Group, announced today positive
results in the development of a vaccine for the global prevention of
dengue fever, one of the most widespread tropical diseases. The
results are being presented today at the American Society of Tropical
Medicine and Hygiene (ASTMH)'s 56th annual meeting held in
Philadelphia, Pennsylvania, USA.

These results have prompted Sanofi Pasteur to immediately expand
ongoing clinical trials in Asia and Latin America. Submission to
health authorities for registration is anticipated in 2012.

"Sanofi Pasteur made research for a vaccine against dengue fever
one of its top priorities by investing in the most promising
technology and dedicating top scientists to this lifesaving project,"
said Wayne Pisano, President and Chief Executive Officer of Sanofi
Pasteur. "Sanofi Pasteur's goal is to make dengue fever a
vaccine-preventable disease as quickly as possible with a vaccine
available to people living in endemic countries or traveling to
tropical destinations."

Immunization with Sanofi Pasteur's tetravalent dengue candidate
vaccine generated a sero-neutralizing antibody response against all
four serotypes of the virus responsible for dengue fever in 100
percent of adults who participated in a trial in the United
States.(1)

"Developing a dengue vaccine has been a major challenge for over a
decade, and we are very pleased with the breakthrough progress made
by Sanofi Pasteur with its tetravalent dengue vaccine," said Harold
Margolis, MD, Director of the Pediatric Dengue Vaccine Initiative
(PDVI). "We believe this moves the world closer to a dengue vaccine
that will be available for people who most need it."

Dengue fever is a mosquito-borne disease affecting up to 100
million people each year and resulting in 24,000 deaths, mostly among
children, according to estimates from the World Health Organization
(WHO).(2),(3) Overall, the disease is a potential threat for close to
half the world's population. Dengue disease if often cyclical and
causes spikes in demand on local medical resources and places
tremendous pressure on strained hospitals and clinics located in
endemic countries.

Dengue fever occurs mostly in tropical and subtropical countries
and it is spreading to new parts of the globe each year. For example,
outbreaks recently have been observed in Paraguay and the Middle
East. In addition, dengue affects countries such as Australia
(Queensland) and the United States (Puerto Rico, Texas-Mexico border,
Hawaii and the US-affiliated Pacific Islands). A substantial number
of people traveling to endemic regions are also infected each year.

Sanofi Pasteur's tetravalent dengue candidate vaccine is based on
a new technology incorporating the protein envelopes that provide
immunity against the four virus types responsible for dengue fever
and the most severe forms of the disease-dengue hemorrhagic fever and
dengue shock syndrome.

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 :
SAN) and in New York (NYSE : SNY).

Sanofi Pasteur, the vaccines division of sanofi-aventis Group,
provided more than a billion doses of vaccine in 2006, 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 http://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
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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-looking
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, 2006. Other than as required by applicable
law, sanofi-aventis does not undertake any obligation to update or
revise any forward-looking information or statements.

(1) Data analyzed by the WHO Flavivirus Laboratory Reference
Center, Mahidol University, Bangkok, Thailand

(2) State of the art of vaccine research and development.
WHO/IVB/06.01

(3) World Health Organization, What is dengue? What is dengue
haemorrhagic fever? Available
at: http://whqlibdoc.who.int/hq/2001/WHO_CDS_CPE_SMT_2001.9.pdf

Sanofi Pasteur
Pascal Barollier
Media Relations
Tel: +33(0)4-37-37-51-41
pascal.barollier@sanofipasteur.com
Sanofi Pasteur
Len Lavenda
Media Relations US
Tel: +1-570-839-4446
len.lavenda@sanofipasteur.com

ots Originaltext: sanofi-aventis Group
Im Internet recherchierbar: http://www.presseportal.de

Contact:
Sanofi Pasteur, Pascal Barollier, Media Relations, Tel:
+33(0)4-37-37-51-41, pascal.barollier@sanofipasteur.com; Sanofi
Pasteur, Len Lavenda, Media Relations US, Tel: +1-570-839-4446,
len.lavenda@sanofipasteur.com