Flu Facts

Influenza (flu) is a contagious respiratory illness caused by flu viruses. It can cause mild to severe illness, and at times can lead to death. People at higher risk of severe illness due to flu infection include adults 65 years and older, people with certain chronic health conditions, pregnant people, and young children.

The Centers for Disease Control and Prevention (CDC) recommends that everyone six months and older, with rare exception, receive a flu shot each year. There are certain flu vaccines that are preferentially recommended for people 65 years and older. For more information on CDC’s recommendations, please visit: Who Needs a Flu Vaccine | CDC.

Flu vaccines work by causing antibodies to develop in the body that provide protection against influenza virus infection. Antibodies develop about two weeks after vaccination. Flu viruses change over time, which is part of why we need to get another flu vaccine each year. The vaccine components are updated each year to keep up with these changes. Another reason is that a person’s immune protection from the flu vaccine wanes over time. For more information on flu vaccines, visit: Key Facts About Seasonal Flu Vaccine | CDC.

Antiviral drugs can be used to treat a flu infection. They work best when started within two days of symptom onset. They can lessen symptoms of the flu and even prevent certain flu complications. For more information on antiviral drugs for flu, visit: Flu Treatment | CDC.