While a common cold is a milder respiratory illness, influenza is a severe infection of the respiratory tract that can lead to serious health complications. The misconception that influenza is just a "very bad cold" is dangerous as seasonal influenza is known to lead to serious health problems like pneumonia and result in death.

In tropical countries like India the virus circulates around the year and an Influenza outbreak can occur any time. It is the unpredictability of the virus that causes concern, hence an annual influenza vaccination is recommended as a precautionary measure since a person may pass on the influenza virus to someone else even before they know that they are sick. The continuous mutation of the influenza virus makes it potentially dangerous as the virus becomes resistant to medicines and results in seasonal epidemics.