What is influenza?
Influenza is a serious respiratory illness caused by a group of viruses. Influenza outbreaks occur every year, usually in the winter months, although new influenza strains may appear at any time.
Vaccination is the first line of defense against influenza. Regular seasonal influenza vaccine, given as an injection ('flu shot') or nasal spray, is updated annually and given each year for continuing protection. The effectiveness of influenza vaccines may vary depending on the age of those vaccinated and how closely the strains included in the vaccine match the strains causing illness.
Where can I learn more?
Information about Influenza from other sources: