Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. It can cause mild to severe illness and, at times, can lead to death. The best way to prevent the flu is by getting vaccinated each year. https://prachicmi.livepositively.com/seasonal-influenza-vaccines-understanding-types-effectiveness-and-more/new=1