Did you know that the flu vaccine is the number one selling vaccine in America, but it is also the least effective? Each year, pharmaceutical companies produce over 150 million doses of influenza vaccine. Each dose sells for about $20, making flu vaccination a $3 billion annual industry. Over the past decade, annual flu vaccine effectiveness has varied between 10 and 60 percent. Last year’s flu vaccine was only 19 percent effective. That means for 80 percent of those who got the vaccine, it didn’t work. For most people, healthy diet, exercise, and lifestyle keep the immune system ready to handle influenza. Rarely, the flu can be more serious for people with heart and lung disease and immune disorders. But the CDC recommends flu vaccine for almost every individual in the United States, including all pregnant mothers, infants, children, adults, and the elderly, regardless of risk factors.