Clinical guidance

Flu Vaccine Q&A

Published January 1, 2022

Updated May 6, 2024

It’s recommended that all adults get an influenza (flu) shot every year in September or October.

Why should I get a flu vaccine?

Getting a flu vaccine every year is the best way to lower your risk of getting sick with the flu.

The flu is an illness that affects the nose, throat, and lungs. Some people get a little sick from the flu, while others get really sick. Each year in the U.S., the flu kills thousands of people and sends hundreds of thousands to the hospital.

Because the flu spreads easily from person to person, getting a flu vaccine also helps prevent other people from becoming sick with the flu.

What do I need to know about the flu vaccine?

There are a few types of flu vaccines for people younger than 65, and a few others for people 65 years and older. All flu vaccines are considered safe and effective. The flu vaccine is usually a single shot in the arm.

When should I get a flu vaccine?

For most adults, getting vaccinated against flu every September or October gives the best protection. That's because flu cases tend to rise at the end of October. (Flu cases usually start to go down around December to February.)

Where can I get a flu vaccine?

The flu vaccine is widely available (you don’t even need a prescription or provider’s order). Your best bet is to get it at a pharmacy near you.

Are there any side effects to getting the flu vaccine?

Some people have side effects, like a sore arm where the shot was given, feeling tired, feeling achy, and a headache. Any side effects are usually mild and don't last long, especially when compared to symptoms of the flu.