Sanofi Pasteur is the vaccines division of the multinational pharmaceutical company Sanofi. Sanofi Pasteur is the largest company in the world devoted entirely to vaccines.

Sanofi Pasteur is one of four global producers of the yellow fever vaccine.

In 1994, Aventis merged with and into Sanofi. The new Sanofi-Aventis Group became the world’s 3rd largest pharmaceutical company. Aventis Pasteur, the vaccine division of Sanofi-Aventis Group, changed its name to Sanofi Pasteur.

Sanofi Pasteur is at the forefront of developing immunological solutions to prevent diseases for every stage of life. Sanofi Pasteur is continuously harnessing new scientific knowledge and technologies to design safe and effective single-entity and combination vaccines against complex diseases for the world population.

The company has major production sites in France, the United States, Argentina, Canada, China, India, Mexico and Thailand. 

According to en.wikipedia