These three important health tools would be vaccination, prevention and treatment.
A yearly flu vaccination can reduce your chances of contracting flu, or reduce the severity of the illness. A vaccination is required yearly as the flu virus mutates rapidly.
There are various preventative measures one can take, including washing your hands often and covering your coughs and sneezes. Also, stay at home during the most contagious stage of flu.
Finally, treatment of flu can minimise the impact of flu. Although there is no antidote for flu, there are various measures one can take to minimise the effects. These include rest, hydration and taking an antibiotic to treat secondary bacterial infections.