With an estimated 3 to 5 million cases of the flu reported each year and more than 250,000 of those resulting in death, the flu virus remains a must-know topic. While each patient's body fights the invading virus, scientists around the world are looking for ways to boost immune systems and even eradicate strains. However, with so many different types of flu and mutations, the fight is an uphill one. This fascinating look at the flu and the science of viruses is presented with fact boxes, quotes from experts, and accessible explanations of the cutting-edge treatments being explored today.