Sanofi Pasteur helps you guard against getting sick in the first place. The company is the US unit of Sanofi Pasteur SA, the vaccines division of French drugmaker Sanofi. It researches, makes, and markets about 20 vaccines that protect against such bacterial and viral diseases as diphtheria, hepatitis, polio, and meningitis. Some of Sanofi Pasteur's top sellers are Fluzone influenza vaccines, childhood combination vaccines, and adult booster shots. It also makes travelers' vaccines that keep globetrotters safe from typhoid, cholera, yellow fever, and the like.