Why do healthy people need influenza immunisation?

I’m fit and healthy, so do I need an annual flu shot?

Answer: 

Healthy adults, children and infants can still become seriously ill and even die.

Also, healthy people can spread influenza to others around them. 

Although people with underlying medical conditions, like asthma or diabetes, are most at risk from flu-associated complications, previously fit and healthy people have ended up in hospital or died from this serious illness.