" According to the Centers for Disease Control, flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and sometimes the lungs. It can cause mild to severe illness, and at times can lead to death. The CDC estimates that influenza has resulted in between 9.3 million – 49.0 million illnesses, between 140,000 – 960,000 hospitalizations and between 12,000 – 79,000 deaths annually since 2010. Studies have proven ...