Influenza (Flu)

What is it?

Contagious respiratory illness caused by influenza viruses that infect the nose, throat, and sometimes the lungs.

Common Symptoms

Fever, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, and fatigue

How is it transmitted?

Flu is transmitted by airborne droplets. It can be spread to others before you know you are sick, as well as when you have symptoms. People with flu are most contagious in the first 3-4 days after the onset of the illness, but it is possible to be contagious at least one day before and up to five to seven days after infection, if not longer.

Flu spreads mainly by tiny airborne droplets made when people with flu cough, sneeze, or talk, and these droplets end up in another nearby person’s mouth or nose. (Touching a surface is possible, but is believed to be less common.)

Who does it primarily affect?

Children are most likely to get sick from the flu and people 65 and older are least likely to get sick from the flu.

(According to a 2018 CDC study, an average of 8 percent of the U.S. population gets sick from flu each season.)

Is there a vaccine?

Yes, but for the most adequate protection, a flu vaccine is needed each year because a person’s immune protection declines over time, and also because flu viruses are constantly changing.

What other prevention steps can you take for Influenza?

The most important thing you can do is to get your annual flu vaccine.

Visit CDC updated recommendations for more information.

Is there anything else I should know about Flu?

Seasonal influenza viruses are detected year-round, but flu season typically lasts from October through April with peak months of December through February.