This year’s flu outbreak is shaping up to be the worst in a decade. Why does it vary so much season to season?
Influenza kills 36,000 Americans and 500,000 worldwide each year.
The H7N9 virus has proven deadly in China, but it is not yet a pandemic.
Already got a flu shot? There’s more you can do to stay healthy.
It takes 2 weeks after a flu shot for the body to develop immunity.
Vaccine gives the body a head start in fighting the virus