The Basics: Overview
Everyone age 6 months and older needs to get a flu shot (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, flu can cause asthma attacks in people with asthma)
- Lead to hospitalization or death
The flu spreads easily from person to person. When you get a flu vaccine, you don’t just protect yourself. You also protect everyone around you.
When do I need to get the seasonal flu vaccine?
Get a 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 to spread in your community.
Flu season can be different from year to year. It can start as early as October and last as late as May. Most years, flu season is between December and February.
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 when someone with the flu coughs, sneezes, or talks. It's also possible to get the flu by touching a surface or object that has flu virus on it and touching your mouth, nose, or eyes.
Symptoms of the flu may include:
- Sore throat
- Runny or stuffy nose
- Muscle or body aches
- Fever of 100 °F or higher
- Feeling feverish or having chills
- Vomiting (throwing up) and diarrhea (frequent, watery poop)
Remember, not everyone with the flu has a fever.
The Basics: Flu Shots
How is the flu vaccine given?
Most people get the flu vaccine as a shot. A nasal spray is available but it's not recommended because it doesn't provide the same protection as the shot.
The best way to protect yourself and others around you is to get a flu shot every year.
Are there any side effects from the seasonal flu vaccine?
Most people don’t have any side effects after getting a flu shot. Some people may have mild side effects that begin soon after the vaccine is given and usually last 1 to 2 days.
Side effects may include:
- Soreness, redness, or swelling where the shot was given
- Low fever
These side effects aren’t the flu. You can’t get the flu from the flu shot because it’s made from killed flu viruses.
The Basics: Am I at Risk?
Am I at high risk for serious 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 a vaccine before the flu starts to spread in your community.
If you care for or spend time with someone at high risk from the flu, you can protect both of you by getting a flu vaccine.
The Basics: Flu Medicine
Is there medicine that can treat the flu?
Yes. If you get sick with the flu, your doctor may prescribe medicines called antiviral drugs. Antiviral drugs can help you feel less sick and shorten the time you are sick.
If you are at high risk for complications from the flu, it’s important to ask your doctor about antiviral drugs right away.
Antiviral drugs work best in the first 2 days after you get sick, but they may still help if you take them later on, especially if you are very sick.
Get the facts about flu antiviral medicine.