The Basics: Overview
Everyone age 6 months and older needs to get a flu vaccine every year. The seasonal flu vaccine is the best way to protect yourself and others from the flu.
For many people, the seasonal flu is a mild illness. But for some people, the flu can be dangerous or even deadly.
The flu can sometimes:
- Cause serious infections like pneumonia (“noo-MOHN-yah”)
- Make existing health problems worse (for example, asthma)
- Lead to hospitalization or death
The flu spreads easily from person to person. When you get the flu vaccine, you don’t just protect yourself – you also protect everyone around you.
The Basics: Flu Symptoms
What is the flu?
The flu is caused by viruses that infect your nose, throat, and lungs. It’s easily spread from person to person.
Symptoms of the flu may include:
- Sore throat
- Runny or stuffy nose
- Body aches
- Fever of 100°F or higher
- Feeling feverish or having chills
Remember, not everyone with the flu has a fever.
The Basics: People at Higher Risk
Am I at high risk for complications from the flu?
For some people, the flu is more likely to cause serious illness that can lead to hospitalization or even death.
People at high risk for getting complications from the flu include:
If you are at high risk from the flu, it’s very important to get the vaccine before the flu starts to spread in your community.
If you spend time with someone at high risk from the flu, you can protect both of you by getting a flu vaccine.
The Basics: Vaccine Options
When do I need to get the seasonal flu vaccine?
Get the flu vaccine soon after it’s available each year – if possible, by October. After you get the vaccine, it takes about 2 weeks for your body to develop protection against the flu. That’s why it’s a good idea to get the vaccine before the flu starts spreading in your community.
Flu season is different from year to year. It can start as early as October and last as late as May.
How is the flu vaccine given?
Most people get the flu vaccine as a shot. But some people may choose to get the flu vaccine as a nasal spray instead.
Is the flu nasal spray right for me?
Flu nasal spray isn't recommended for everyone. People who can't get the nasal spray include:
- Children under age 2
- Adults over age 50
- Pregnant women
- People with weakened immune systems
Learn more about the nasal spray flu vaccine.
The Basics: Vaccine Side Effects
Are there any side effects from the seasonal flu vaccine?
Most people don’t have any side effects after getting the flu vaccine. Some people may have mild side effects. These side effects begin soon after the vaccine is given and usually last 1 to 2 days. These side effects aren’t the flu.
People who get the flu shot may feel achy or have a sore arm where the shot was given. You can’t get the flu from the flu shot because it’s made from killed flu viruses.
Flu nasal spray
People who get the nasal spray may have a stuffy nose and sore throat afterward. The flu viruses in the nasal spray are weakened and can’t cause the flu.
Check out these key facts about the seasonal flu vaccine.