Flu Shot FAQs: Your Top Flu Vaccine Questions Answered

Flu season comes around every year, and so do plenty of questions.

Is the flu shot effective? When's the best time to get vaccinated? Can it make you sick?

We've answered some of the most common questions to help you and your loved ones stay protected this season.

Why is a flu shot important?

Every year, millions of people are affected by the flu.

Getting a flu shot is the best way to protect yourself against the flu and lower your risk of flu-related complications, such as:

• Pneumonia
• Sinus and ear infections
• Worsening of chronic health conditions
• Hospitalization

Who should get a flu shot?

Everyone 6 months and older, with rare exceptions, should get a flu shot every flu season.

Flu vaccination is especially important for people at higher risk of developing serious flu-related complications, including:

• Children under 2 years old
• Pregnant women
• Adults age 65 and older
• People with certain health conditions (such as asthma, chronic lung or heart disease, kidney, liver, or metabolic disorder)

Why do you need a flu shot every year?

Getting a flu shot each flu season is recommended for two important reasons:

1. Immunity decreases
   Over time, the immunity your body builds after receiving your flu shot naturally declines.
2. Every flu season is different
   Influenza (flu) strains are always changing. Each year, experts review circulating strains and update the seasonal flu vaccine to help protect against the viruses most likely to spread during the upcoming flu season.

When is the best time to get your flu shot?

It's recommended to get your flu vaccine in September or October before the flu starts to spread in your community. This timing is important because it takes about two weeks after vaccination for your body to build protection against the flu.

If you miss that window, don't worry. Getting a flu shot later in the season can still help protect you against the flu.

Can the flu shot give you the flu? 

No. A flu shot cannot give you the flu.

The flu shot contains “inactive” viruses, meaning the virus in the flu shot is no longer alive or infectious.

After getting your flu shot, you may experience mild side effects, including:

• Soreness, redness, or tenderness around the injection site
• Low-grade fever
• Headache and muscle aches
• Running nose, cough, sore throat

These side effects usually go away within a few days. If your symptoms become severe or worsen over time, seek medical care.

Can you get a flu shot if you’re sick?

It depends.

If you have mild symptoms, such as a cold, it's generally safe to get your flu shot.

But if you have moderate to severe symptoms, such as a high fever, it's best to wait until you recover.

Can pregnant women get a flu shot?

Yes, pregnant women can still get a flu shot to protect both the mother and her baby from the flu.

Pregnant women should not receive the nasal spray vaccine as a form of flu vaccination.

If you are pregnant or planning to become pregnant, talk with your doctor about the best vaccination plan for you.

If you have questions about the flu vaccine, talk with your doctor. For more information about flu shots, visit our flu shot page.