Vaccines: Poised To Deliver Significant Growth in Emerging Markets4th DVFA Symposium Life SciencePierre MorgonVice-President, Franchise & Global Marketing Operations, Sanofi Pasteur

Frankfurt, May 17, 2011

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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-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 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 labelling 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-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, 2010. Other than as required by applicable law, sanofi-aventis does not undertake any obligation to update or revise any forward-looking information or statements.

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Agenda

● Emerging Markets and Vaccines: Two Growth Platforms for Sanofi

● Sanofi Pasteur: a Global Leader in Vaccines Committed to Public Health

● Sanofi Pasteur: Capturing Growth Opportunities in Emerging Markets

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Developing Sustainable Growth Platforms

Emerging Markets

DiabetesSolutions

Consumer Health Care

HumanVaccines

Animal Health

Innovative Products

®

Rare Diseases

5Expanding our Unparalleled Leadership Position in Emerging Markets

In 2010Emerging

Markets(1) sales€9.1bn, +16.3%(2)

30%of consolidated

sales

Pharmacy in Brazil

(1) World less North America, Western Europe, Japan and Australia/New Zealand (2) Growth at constant exchange rates.

6: a Global Leader in Vaccines Committed to Public Health

In 2010

More than 1 billiondoses of vaccines

to immunizemore than 500m people

throughout the world

Vaccines consolidated sales€3.8bn, +4.8%(1)

(1) Growth at constant exchange rates

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Agenda

● Emerging Markets and Vaccines: Two Growth Platforms for Sanofi

● Sanofi Pasteur: a Global Leader in Vaccines Committed to Public Health

● Sanofi Pasteur: Capturing Growth Opportunities in Emerging Markets

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Vaccines – Strategic Segment of Health Care

● Most cost-effective health-care intervention available

● High degree of innovation and limited exposure to generics

● Improved pricing due to significant health benefits

● Significant unmet demandin emerging markets

● One of the fastest growing markets

(1) Estimated birth cohorts in millions, Census Bureau, updated November 26, 2009

India: 25.1m

U.S.: 4.2m China: 18.7mWestern EU:

4.0m

Mexico: 2.2m

Brazil: 3.7m

Russia: 1.6m

Largest birth cohorts in emerging markets(1)

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Sanofi – A Unique Position in Vaccines

● A strong heritage

● A broad and diversified product offering

● A success story based on leadership and innovation

● Leadership in Influenza, Meningitis and Pediatric vaccines

● New wave of innovation in preparation with vaccines against Dengue Fever and Clostridium Difficile

(1) Growth at constant exchange rates (2) Accounted for using the equity method(3) Based on reported FY2010 results and Sanofi Pasteur internal estimates for “Others” – Sanofi Pasteur MS estimate includes 50% of Sanofi Pasteur MSD sales, excluding pandemic sales

A Global Leader in Vaccines

Pandemic Influenza

12%

Seasonal Influenza

22%

Polio/Pertussis/

Hib26%

Boosters12%

Meningitis/Pneumonia

14%Travel & Endemics

10%

Other4%

FY2010Sales %

by Franchise

● FY2010 sales: €3,808m, +4.8%(1)

● JV with Merck in EU: €918m(2)

● 22% market share in 2010(3)

Diversified and Balanced Portfolio

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Sanofi Pasteur – Good Start to the Year 2011

● Q1 2011 Sales: €602m, +9.6% at CER excluding A/H1N1(1)

● Strong Emerging Markets sales of€282m, +37.1% at CER excluding A/H1N1, driven by:● Record seasonal flu campaign

● Solid growth of

● Good performance of and in the U.S.

● FDA approval granted for for infants and toddlers

(1) Q1 2011 sales decreased by -38.3% at constant exchange rates when including €413m of A/H1N1 vaccine sales in Q1 2010

Q1 2010 Q1 2011

Polio/Pertussis/Hib Seasonal InfluenzaMeningitis/Pneumonia BoostersTravel & Endemics OtherPandemic Influenza

Vaccines Consolidated Sales (€m)

A/H1N1€413m €602m

11Historical Performance Driven by the U.S. and Europe - Still Room to Grow

● Highly concentrated market● 4 large international players

● High immunization rates● Opportunities remain in all age

segments

● Differentiation as competitive advantage

● Further growth to come from life cycle management and innovative vaccines

Market Share by Major FranchiseYTD December 2010(1)

(1) 2010 Competitors’ annual earnings statements and Sanofi Pasteur internal sales data(2) Seasonal influenza - Internal projections based on published CDC and manufacturer statements

U.S.: Market Leader Everywhere We Compete

68% 68%51%

95%

32% 32%49%

0%

20%

40%

60%

80%

100%

PediatricPertussis

Boosters Flu Meningitis

Sanofi Pasteur All other competitors

(2)

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2010-2015CAGR15%

Significant Future Growth to Be Fuelledby The Emerging Markets

● Large population and birth cohorts

● Low immunization rates

● Economic growth driving middle class and private sector expansion

● Expansion of government healthcare coverage

● Many unmet medical needs

Projected Emerging Market(1)

Vaccines Sales(2) (€bn)

2

5

10

2005 2010e 2015e

(1) Emerging markets includes Asia-Pacific (excluding Japan, Australia and New Zealand), Africa, Middle-East, Eastern Europe and Latin America

(2) Sanofi Pasteur internal estimates excluding pandemic influenza sales

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Agenda

● Emerging Markets and Vaccines: Two Growth Platforms for Sanofi

● Sanofi Pasteur: a Global Leader in Vaccines Committed to Public Health

● Sanofi Pasteur: Capturing Growth Opportunities in Emerging Markets

14Sanofi Pasteur Has a Well Established Presence in Emerging Markets

Sales growth is at constant exchange rates(1) Including pandemic vaccine sales (2) Includes Turkey

Africa &Middle EastSales in 2010(1): €226m, +16%

EasternEurope(2)

Sales in 2010(1): €166m, +33%

AsiaSales in 2010(1): €342m, + 21%

Latin AmericaSales in 2010(1): €601m, + 116%

FY 2010Sanofi Pasteur sales in Emerging Markets

Ranks #1€1,386m(1), +46.2%

€1,025m, +15.4%, excluding Pandemic Influenza

15Ensuring Long-Term Growth Through Tailored R&D, Industrial and Commercial Footprint

Emerging MarketsIndustrial and R&D Presence

GPO Thailand

● Present in over 100 countries

● Investing in local manufacturing ● 4 international sites: China, Thailand,

Argentina and India● 2 sites under construction:

China and Mexico

● Regional approaches for R&D project execution● 2 main centers: China and India

● Shantha a strategic asset● Cost-effective manufacturing base

● Offering adapted to UNICEF/GAVI segment

● R&D pipeline (Rotavirus, HPV) Industrial site R&D site

Ocoyoacac

Beijing

Shenzhen

ShanthaPilar

16A Strong Record of AlliancesTo Access Emerging Markets

● Partner of choice

● Over 14 partnerships

● Built long-standing relationships

● New partnerships in development

Selected Sanofi Pasteur Partnershipsin Emerging Markets

Birmex

ButantanThe BiovacInstituteEPI

MEFAR Chumakov

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A Solid R&D Pipeline to Fuel our Growth

Developed Emerging Developed & Emerging

Primary Target Market

Fluzone® QIVQuadrivalent inactivated influenza

vaccine

Quadracel®Diphtheria, tetanus, pertussis and polio

vaccine; 4-6 years of age

Hexaxim™DTP-HepB-Polio-Hib vaccine

DengueMild-to-severe

dengue fever vaccine

DTP-HepB-Polio-HibPediatric hexavalent vaccine

Meninge ACYW conj.2nd generation meningococcal

conjugate Infant vaccine

ACAM-CdiffClostridium difficile

Toxoid vaccine

RotavirusLive Attenuated Tetravalent

Rotavirus oral vaccine

TuberculosisRecombinant subunit vaccine

Streptococcus pneumoniaMeningitis & pneumonia vaccine

Pseudomonas aeruginosaAntibody fragment product

Prevention ofventilator-associated pneumonia

Rabies VRVgPurified vero rabies vaccine

RabiesmAb post exposure prophylaxis

Phase IIIPhase IIPhase I

18A Broad Product Offering Well Suited for Emerging Markets

Polio/Pertussis/Hib€384m, +11.4%

Sesaonal Influenza€257m, +10.9%

Meningitis/Pneumo€101m, +25.6%

Boosters€33m, +32%

Others€15m

Travel & other endemics€235m, +15.8%

®

2010 Sanofi Pasteur Sales Performance in Emerging Markets(1)

(1) Sales growth at constant exchange rates

Pandemic Influenza€361m

Shanchol

19A Pediatric Combo PortfolioTailored to Emerging Markets

5-component acellular Pertussis

2-component acellular Pertussis

Unmatched capacity for Oral and Inactivated Polio Vaccines

3 combo families to address different market cluster needs

Hexaxim™First launches expected end of 2013

Pediatric combination includes Diphtheria, Tetanus, Pertussis, inactivated Polio, plus Haemophilus b and/or Hepatitis B depending on vaccine

Whole cell Pertussis

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Seasonal Influenza Vaccines

● Northern Hemisphere: ~40% MS(1)

● Southern Hemisphere: ~70% MS(1)

● 2010 net sales of €257m in Emerging Markets

● New differentiated offering

The Broadest Seasonal Influenza Vaccines Offering of the Industry

Unique Manufacturing Platform

Existing sitesUnder Construction

Ocoyoacac

ShenzhenSwiftwater

Val de Reuil

First intradermalinfluenza vaccine

(1) Market shares (MS) based on reported FY2010 results and Sanofi Pasteur internal estimates for other companies (includes allcountries in a given hemisphere)

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Dengue: A Growing Health Concern

● Mosquito-borne disease

● 2nd most widespread tropical disease after Malaria

● 2.5bn people in tropical and subtropical region; annual incidence of 50-100m cases● Increasing geographic spread

and burden of disease ● High economic burden in endemic

countries

● No effective drug treatments

● No effective prevention

(1) Sources: WHO

Global Prevalence of Dengue(1)

Areas infested with Aedes aegypti

Areas with Aedes aegypti and dengue epidemic activity

22Developing a Safe and EffectiveTetravalent Vaccine against Dengue

● ChimerivaxTM technology

● Phase III study on-going

● Over 15 countries involved

● Around 39,000 subjects recruited including around 11,000 children

● Expected to be first to market

● Market estimated to be over €1 billion

● First submissions planned in 2013

● Partnering Dengue Vaccine Initiative (DVI)

Dengue FacilitiesConstruction Status (Neuville,

France)

100m dose capacityTo be online end 2013

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● Sales contributing to Polio eradication of €48m in 2010(1)

● Broad portfolio adapted to market● Complementary Sanofi Pasteur/

Shantha vaccines range

● Strong presence in pediatric vaccines with

● Expanded presence and coverage

● OPV vaccine supplier

● Sales of €104m in 2010(1)

● Leadership position in flu

● Shenzhen plant construction and validation finalized

● Growth driven by both pediatric and adult vaccines

● Continuing history of first-to-market (Flu, Hib, Pneumo, and IPV)● Launch of in May 2011

Sanofi pasteur in Asia

IPV: Inactivated Polio vaccine OPV: Oral Polio vaccine(1) Including pandemic vaccine sales

China India

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● Sales of €185m in 2010(1)

● Flu leadership position

● Local production platform in construction

● Pediatric combo vaccine leadership

● Growth driven by introduction of new vaccines in the public market

in Latin America

(1) Including pandemic vaccine sales

Brazil Mexico● Sales of €294m in 2010(1)

● Flu leadership position

● Delivered Yellow Fever for outbreak control

● Introduction of new vaccines

● Preparing Dengue vaccine introduction into public sector

25Ensuring Long-term Growth in Emerging Markets

● Broad vaccines offering adapted to local needs

● Strong industrial and commercial presence

● Key local partnerships

● Regional base

● Promising projects in development