SANOFI : Brazil Introduces Inactivated Polio Vaccine in National Immunization Program with Sanofi Pasteur Vaccine

PRESS RELEASE

Brazil Introduces Inactivated Polio Vaccine in National Immunization Program with Sanofi Pasteur Vaccine - Supply of injectable inactivated polio vaccine, a major step in the world's fifth most populous country made possible by partnership between Sanofi Pasteur and Bio- Manguinhos, the Institute of Technology in Immuno-biologicals of Fiocruz -

Lyon, France - January 18, 2012 - Sanofi Pasteur, the vaccines division of Sanofi (EURONEXT: SAN and NYSE: SNY), announced today that Brazil has chosen to introduce injectable polio vaccine in its national immunization program with inactivated polio vaccine (IPV) from Sanofi Pasteur. The IPV doses will be provided by Bio-Manguinhos, the Institute of Technology in Immuno- biologicals of the Oswaldo Cruz Foundation (Fiocruz), through an agreement with Sanofi Pasteur. IPV will be included in the Brazilian national immunization program starting in 2012.

"Injectable polio vaccine is the standard of care for polio vaccination in polio-free countries. Sanofi Pasteur commends the decision made by Brazil to introduce this vaccine in its public immunization program," said Olivier Charmeil, President and CEO of Sanofi Pasteur. "We are very pleased to contribute again to Brazilian public health history by partnering with the Oswaldo Cruz Foundation to ensure the availability of IPV to millions of children in Brazil."

The WHO region of the Americas was certified polio-free in 1994(1). The Brazilian Immunization
Program will include two doses of IPV followed by two doses of OPV (oral polio vaccine).

"This initiative strengthens Fiocruz's position as a strategic state health institution. We are very proud to be adding IPV, which will provide immunization to nearly 3 million children annually, to the contributions already made in the vaccine field," said Dr. Paulo Gadelha, President of Fiocruz.

Over 60 polio-free countries are using IPV

An increasing number of polio-free countries are including IPV in their national polio immunization programs. As of today, more than 800 million doses of Sanofi Pasteur IPV and IPV containing vaccines have been distributed worldwide.

Sanofi Pasteur, an historical partner to Brazil public health

In 1974, Institut Mérieux (now Sanofi Pasteur) responded to a request from the Brazilian Ministry of Health to help fight a meningitis epidemic that was sweeping the country. The company provided meningococcal vaccine doses to vaccinate 90 million Brazilians, bringing to an end the meningitis epidemic. In 2008, Sanofi Pasteur shipped millions of doses of yellow fever vaccines to Brazil in response to emergency requests to help fight a yellow fever epidemic. In 2010, during the H1N1 pandemic, Sanofi Pasteur partnered with the Brazilian ministry of health to provide over 60 million doses of H1N1 vaccines.

About the Oswald Cruz Foundation (Fiocruz)

The Institute of Technology on Immunobiologicals (Bio-Manguinhos), which celebrates its 35th
anniversary in 2011, is the unit of Fiocruz in charge of the technological development and production of vaccines, reagents for diagnosis and biopharmaceuticals. Its primary mission is to meet national public health needs. In 2011, it provided the National Immunization Program of the

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Ministry of Health with around 141 million doses of vaccines. Currently, it is in charge of providing 6 out of the 13 immunizing agents included in the national basic schedule and allocates the surplus of the yellow fever and meningococcal A/C vaccines to the World Health Organization (WHO), the Pan American Health Organization (PAHO) and the United Nations Children's Fund (UNICEF). It is the leading provider of immunizing agents with over 50% public market share.

About poliomyelitis

Poliomyelitis (polio) is a highly infectious disease caused by a virus that invades the nervous system and can cause severe paralysis. The virus enters the body through the mouth and multiplies in the intestine. Initial symptoms are fever, fatigue, headache, vomiting, stiffness in the neck, and pain in the limbs. One in 200 infections leads to irreversible paralysis (usually in the legs). Among those paralyzed, 5-10% die when their breathing muscles become immobilized. Polio mainly affects children under five years of age. In 1994, the Region of the Americas was certified polio-free by the World Health Organization, followed by the Western Pacific Region in 2000 and the European Region in 2002; worldwide efforts are continuing towards global eradication of this contagious and devastating disease (1).

About Sanofi

Sanofi, a global and diversified healthcare leader, discovers, develops and distributes therapeutic solutions focused on patients' needs. Sanofi has core strengths in the field of healthcare with seven growth platforms: diabetes solutions, human vaccines, innovative drugs, rare diseases, consumer healthcare, emerging markets and animal health. Sanofi is listed in Paris (EURONEXT: SAN) and in New York (NYSE: SNY).
Sanofi Pasteur, the vaccines division of Sanofi, provides more than 1 billion doses of vaccine each year, 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 EUR 1 million in research and development. For more information, please visit: www.sanofipasteur.comor 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 projections and estimates and their underlying assumptions, statements regarding plans, objectives, intentions and expectations with respect to future financial results, events, operations, services, product development and potential, 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's 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, 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 among other things, the uncertainties inherent in research and development, future clinical data and analysis, including post marketing, decisions by regulatory authorities, such as the FDA or the EMA, regarding whether and when to approve any drug, device or biological application that may be filed for any such product candidates as well as their decisions regarding labeling and other matters that could affect the availability or commercial potential of such products candidates, the absence of guarantee that the products candidates if approved will be commercially successful, the future approval and commercial success of therapeutic alternatives, the Group's ability to benefit from external growth opportunities as well as those discussed or identified in the public filings with the SEC and the AMF made by Sanofi, including those listed under "Risk Factors" and "Cautionary Statement Regarding Forward-Looking Statements" in Sanofi's annual report on Form 20-F for the year ended December 31, 2010. Other than as required by applicable law, Sanofi does not undertake any obligation to update or revise any forward-looking information or statements.

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Reference

1. WHO Fact sheet N°114 Poliomyelitis http://www.who.int/mediacentre/factsheets/fs114/en/

Contacts: Global Media Relations Brazil Media Relations

Pascal Barollier Juliane Zache
T. [phone] T. + 55 11 3759-6433 [e-mail] [e-mail]
www.sanofipasteur.com

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