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Sanofi Pasteur Announces Results of U.S. Clinical Trials of Influenza A (H1N1) Vaccine in Infants and Children

The first clinical trial data from America’s youngest vaccine recipients, children 6 months through 9 years of age, show the vaccine induces an immune response and is well-tolerated

Data indicate that two doses of vaccine will be required for optimum protection of children under the age of 10 years

Oct 14, 2009

Swiftwater, Pa (United States) – October 14, 2009 – Sanofi Pasteur, the vaccines division of the sanofi-aventis Group (EURONEXT: SAN and NYSE: SNY), announced today an interim analysis of data from clinical trials of the U.S. licensed Influenza A (H1N1) 2009 Monovalent Vaccine in infants and children 6 months through 9 years of age. The data indicate the vaccine is immunogenic and that one dose may protect many children. However, the study suggests that two doses of vaccine will be required for optimal protection of children under the age of 10 years. This is consistent with the recommendations for seasonal influenza immunization in children of this age. Clinical trials are ongoing to evaluate the immunogenicity and safety in children following two doses of vaccine.


“According to the Centers for Disease Control and Prevention young children are among those of highest priority for immunization with the Influenza A (H1N1) 2009 Monovalent Vaccine, given the relatively high disease incidence and potential for transmission in this population,” said Wayne Pisano, President and Chief Executive Officer of Sanofi Pasteur. “As the only company licensed in the U.S. to produce a pediatric influenza vaccine which is licensed for children as young as 6 months of age, it was the highest priority for Sanofi Pasteur to conduct clinical trials to evaluate the safety and immunogenicity of the pandemic vaccine in children to support decisions on vaccine administration.”


This randomized, placebo-controlled, multicenter trial was conducted by Sanofi Pasteur to determine the immunogenicity and safety of the vaccine, given as a two-dose schedule, 21 days apart. A total of 474 children were enrolled in the trial in two age cohorts: 229 children 6 months through 35 months of age; and 245 children 3 years through 9 years of age. The trial evaluated two antigen doses: formulated as 7.5 mcg and 15 mcg hemagglutinin in each cohort ( registration number NCT00952419). The interim results reported today are the first data available from children under the age of 10 years. Previously, Sanofi Pasteur reported that 98 percent of adults 18 years through 64 years of age had an immune response considered protective following one 15 mcg dose of vaccine.


The clinical trial in children evaluated immune responses to Sanofi Pasteur’s Influenza A (H1N1) 2009 Monovalent Vaccine compared with placebo, based on rates of seroprotection and seroconversion. Two doses of vaccine were administered, the second dose 21 days after the first. Immunogenicity was measured at day 21, just prior to administration of the second dose, and will be measured again 21 days after the second dose at day 42. In both age groups, immune responses 21 days after one dose of the 15 mcg vaccine satisfied the criteria for seroconversion. The criteria for seroprotection were not met with only one 15 mcg dose of vaccine in either age group. In this clinical trial 76 percent of children 3 years through 9 years of age and 50 percent of children 6 months through 35 months of age had immune responses considered seroprotective following one 15 mcg dose of vaccine. An antibody titer of 1:40 or greater is generally considered a marker of seroprotection. A lower rise in antibody titers following vaccination may minimize the occurrence of disease and its consequences but is not considered seroprotective. Final data from these clinical trials, following a second dose of vaccine, will provide additional information to guide recommendations on the optimal dosage, number of doses and schedule.


Adverse events are being monitored throughout the clinical trial and will continue for six months after the second dose of vaccine. No serious adverse events have been reported in the trial to date. Local reactions reported have been similar to those observed with the seasonal influenza vaccine.


About Influenza A (H1N1) 2009 Monovalent Vaccine

The U.S. licensed Influenza A (H1N1) 2009 Monovalent Vaccine manufactured by Sanofi Pasteur is an inactivated influenza virus vaccine indicated for active immunization of persons 6 months of age and older against influenza disease caused by pandemic (H1N1) 2009 virus. Influenza A (H1N1) 2009 Monovalent Vaccine was licensed by the U.S. Food and Drug Administration on September 15 as a monovalent strain change to Sanofi Pasteur’s licensed seasonal influenza vaccine.


The Influenza A (H1N1) 2009 Monovalent Vaccine is manufactured by the same process as Sanofi Pasteur’s seasonal trivalent influenza virus vaccine licensed in the U.S. Influenza A (H1N1) 2009 Monovalent Vaccine is formulated to contain 15 mcg hemagglutinin (HA) of influenza A/California/07/2009 (H1N1) v–like virus. Influenza A (H1N1) 2009 Monovalent Vaccine is licensed for single-dose presentations in syringes and vials and in multi-dose vials. There is no preservative used in the single-dose presentations. Multi-dose vials contain a preservative.


Safety Information for Influenza A (H1N1) 2009 Monovalent Vaccine

Influenza vaccine should not be administered to anyone with a known severe hypersensitivity to egg proteins, any vaccine component or life-threatening reactions after previous administration of any influenza vaccine. Recurrence of Guillain-Barré syndrome (GBS) has been temporally associated with the administration of influenza vaccine. The decision to give Influenza A (H1N1) 2009 Monovalent Vaccine to individuals who have a prior history of GBS should be based on careful consideration of the potential benefits and risks. Vaccination with Influenza A (H1N1) 2009 Monovalent Vaccine may not protect all individuals.


Before administering Influenza A (H1N1) 2009 Monovalent Vaccine, please see full U.S. Prescribing Information at


About Influenza Vaccine Production at Sanofi Pasteur

Sanofi Pasteur operates influenza vaccine production facilities in Val de Reuil, France and in Swiftwater, Pa. (U.S.). All Sanofi Pasteur influenza vaccine facilities have been designed and built to be able to switch from seasonal influenza vaccine production to pandemic influenza vaccine production.

Sanofi Pasteur produces approximately 40 percent of the influenza vaccines distributed worldwide and more than 45 percent of the influenza vaccines distributed in the U.S. for the 2008-2009 influenza season. More information about Sanofi Pasteur’s pandemic preparedness efforts can be found at


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 the sanofi-aventis Group, provided more than 1.6 billion doses of vaccine in 2008, 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: or


Project Funding

This project has been funded with Federal funds from the Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority, under Contract No. HHSO100200900121C. The views expressed do not necessarily reflect the official policies of the Department of Health and Human Services; nor does mention of trade names, commercial practices or organizations imply endorsement by the U.S. Government.


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-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, 2008. Other than as required by applicable law, sanofi-aventis does not undertake any obligation to update or revise any forward-looking information or statements. 

For further information: US Media Relations Donna Cary T. +1-570-957-0717