Aventis Pasteur Donates Approximately 75 to 90 Million Doses of Smallpox Vaccine to The U.S.; Company Also Will Seek to Develop Improved Smallpox Vaccines.

Business Editors

SWIFTWATER, Pa.--(BUSINESS WIRE)--March 29, 2002

Aventis Pasteur, the vaccines business of Aventis Pharma, announced today that it will donate its smallpox vaccine inventory to the U.S. government's emergency preparedness stockpiles.

The inventory is estimated to be between 75 and 90 million doses with the exact amount to be confirmed by clinical studies. The vaccine comes from the company's existing stock and has an estimated commercial value in excess of $150 million. It will provide a short-term safety stock for emergency use during this period of time in which the U.S. may be particularly vulnerable to a terrorist smallpox attack until new vaccine supplies are available.

The company has worked closely with numerous U.S. government agencies since October 2001 to prepare the vaccine for addition to the existing emergency stockpile. However, government agencies had been aware of the existence of the vaccine for many years prior to that date.

Clinical studies will be conducted by the National Institutes of Health to confirm efficacy and to determine the potential for diluting the vaccine, which could result in substantially more doses being available to the stockpile. The availability of this vaccine will help to more quickly achieve Health and Human Services Secretary Tommy Thompson's goal that "every man, woman and child will have a vaccine they can say has their name on it."

The vaccine will be reviewed by the Food and Drug Administration as an Investigational New Drug (IND) for emergency use, with the Centers for Disease Control and Prevention serving as the sponsor.

The company has also started to produce a new cell culture-based smallpox vaccine in Europe, which it anticipates will become available in Europe at the end of the year. In addition, the company has proposed redirecting some of its research efforts towards the development of an improved smallpox vaccine based on its proprietary NYVAC(TM) (highly attenuated vaccinia virus) and other technologies. The NYVAC approach could potentially be used as a next generation smallpox vaccine should a broader immunization effort be contemplated.

"We are offering both short-term and what we hope will be long-term relief from concerns about vulnerability to smallpox as an agent of bioterrorism," said Richard J. Markham, chief executive officer of Aventis Pharma. "HHS has enormous needs placed on it at this point and relatively modest resources given all of the costs surrounding bioterrorism. It's very important to us - as citizens, not just in our role as a vaccine producer - to be able to make a contribution during this time of uncertainty. We hope that a dose will never be needed, but we are gratified that we will be able to contribute to the immediate need for building the stockpile."

The vaccine, which is now in a secure offsite location, has been held in storage since routine smallpox vaccination ended in 1972.

About Aventis

Aventis Pasteur Inc. is located in Swiftwater, PA, and is owned by Aventis Pasteur SA. Aventis Pasteur, a world leader in vaccines with the broadest range of products, produces more than one billion doses of vaccines every year to immunize 400 million people around the world.

Aventis Pasteur Inc. provides the broadest range of human vaccines and biologicals commercially available from any single U.S. vaccine company. It is a leading supplier of vaccines to protect against diphtheria, tetanus, pertussis, polio, Japanese encephalitis, yellow fever, Haemophilus influenzae type b disease, meningitis, rabies, influenza, and typhoid fever.

Aventis Pharma AG is the pharmaceutical company of Aventis S.A. (NYSE: AVE). Aventis Pharma is dedicated to treating and preventing human disease through the discovery, development, manufacture and sale of innovative pharmaceutical products aimed at fulfilling unmet medical needs. The corporate headquarters of Aventis Pharma is in Frankfurt, Germany. Aventis Pharma is comprised of Aventis Pasteur, a world leader in vaccines, headquartered in Lyon, France, and Aventis Behring, a world leader in therapeutic proteins, headquartered in King of Prussia, Pa.

Aventis (NYSE: AVE) is dedicated to improving life by treating and preventing human disease through the discovery and development of innovative pharmaceutical products. Aventis focuses on prescription drugs for important therapeutic areas such as oncology, cardiology, diabetes and respiratory disorders as well as on human vaccines. In 2001, Aventis generated sales of 17.7 billion Euros ($15.5 billion), invested approximately 3 billion Euros ($2.6 billion) in research and development and employed approximately 75,000 people in its core business. Aventis corporate headquarters are in Strasbourg, France. For more information, please visit: www.aventis.com

Statements in this news release other than historical information are forward-looking statements subject to risks and uncertainties. Actual results could differ materially depending on factors such as the availability of resources, the timing and effects of regulatory actions, the strength of competition, the outcome of litigation, and the effectiveness of patent protection. Additional information regarding risks and uncertainties is set forth in the current Annual Report on Form 20-F of Aventis on file with the Securities and Exchange Commission.