When is the Best Time to Get a Flu Shot?

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When is the Best Time to Get a Flu Shot?

Skye Kalil

Written by Skye Kalil

Skye Kalil

Skye Kalil

Skye likes writing about mental health, nutrition, and wellness. She is passionate about sharing information that will educate, and positively affect people's lives.

September 29, 2021 / Read Time 6 minutes

Updated December 23, 2022

What is the Influenza Vaccine?

The influenza vaccine is used to protect people from contracting influenza. Influenza, commonly called the flu, is a respiratory infection that can be harmful, especially to young children and older adults, and can even cause death. While not 100% effective, the influenza vaccine is the best way to prevent catching the flu. 

Multiple different viruses can cause the flu, and there are many strains of the flu. This constant change is why the Centers for Disease Control and Prevention (CDC) recommends annual flu vaccination for everyone age six months or older. 

Typically, the flu vaccine is given to you by your doctor, or at a pharmacy or drugstore that offers them. They are usually given with a needle in the arm, but a nasal spray flu vaccine is also available. 

  1. 1

    Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

  2. 2

    See a doctor, get treatment and a prescription at your local pharmacy.

  3. 3

    Use your health insurance just like you normally would to see your doctor.

Is the Flu Shot a Vaccine?

Yes, the flu shot is a vaccine, although it is sometimes casually referred to as a flu shot or flu jab. According to the U.S. National Library of Medicine, “the flu vaccine causes antibodies to develop in your body about two weeks after you get it. These antibodies provide protection against infection with the viruses that are in the vaccine.” 

The flu vaccine can only protect you from some strains of the flu. Research indicates which four influenza viruses will be the most common in the upcoming flu season. Because the influenza virus changes so rapidly, scientists develop new versions of flu vaccines twice a year, which is why it is important to get the new flu vaccine every year. 

How Long Does the Flu Shot Last?

The flu shot will last for at least six months. As antibodies wane over time, the immunity to the flu will decrease over time. And as the circulating influenza virus changes year to year, the updated vaccine is needed to combat these changes. Last year's vaccine may not protect you from this year’s flu. 

Read More: How Long Does the Flu Shot Last?

Should You Get a Flu Shot Every Year?

You should consider getting a flu shot every year. It is important to get a new vaccine every year because the flu virus evolves so quickly. Each newly updated vaccine is designed to protect you against the rapidly adapting flu virus. The CDC recommends that everyone six months old, and older should get the flu vaccine every season.

What Is the Best Time to Get a Flu Shot?

Each flu season, a new vaccine is released based on research on how the influenza virus has adapted. The best time to get a flu shot in the US is in September or October. You can get the flu vaccine as soon as it is available, but it is best to get it during the fall, or at least before winter, as that is flu season when the influenza virus infects the most people. 

What Is in the Flu Shot?

The flu shot contains a tiny amount of the influenza virus that the vaccine will protect against. While the virus is in the vaccine, it will not give you the flu, because these viruses are dead, or inactivated, so they cannot cause you to get the flu. 

There are different versions of the flu vaccine, as there are multiple vaccine manufacturers, and multiple influenza vaccine products licensed and recommended for use in the United States. Some of the most popular include: 

  • Quadrivalent inactivated influenza vaccines (IIV4s)

  • Recombinant influenza vaccine (RIV4)

  • Live attenuated influenza vaccine (LAIV4)

What Are the Side Effects of a Flu Shot?

Flu shot side effects can vary from person to person. However, typical side effects of the flu shot include: 

  • Fever

  • Headache

  • Muscle aches and pains

  • Pain, tenderness, redness, or swelling at the injection site

  • Tiredness

There are also some possible side effects that you should report to your doctor immediately if they occur: 

  • Skin rash

  • Itching or hives

  • Swelling of the face, lips, or tongue

  • Other allergic reactions

If you have any abnormal side effects, or side effects do not go away within three days, contact your doctor.

Can the Flu Shot Make You Sick?

Some side effects of the flu shot can make you feel somewhat sick, but the vaccine itself will not make you sick, and you cannot get the flu from the flu vaccine. It also does not increase your risk of contracting COVID-19. 

According to the Mayo Clinic, some reasons that you may develop flu-like symptoms while getting vaccine include:

  • Reaction to the vaccine. Some people experience muscle aches and a fever for a day or two after receiving a flu vaccine. This may be a side effect of your body's production of protective antibodies.

  • The two-week window. It takes about two weeks for the flu shot to take full effect. If you're exposed to the influenza virus shortly before or during that time period, you might catch the flu.

  • Mismatched flu viruses. In some years, the influenza viruses used for the vaccine don't match the viruses circulating during the flu season. If this occurs, your flu shot will be less effective, but may still offer some protection.

  • Other illnesses. Many other illnesses, such as the common cold, also produce flu-like symptoms. So, you may think you have the flu when you actually don't.

How Effective Is the Flu Shot?

The flu shot will vary in effectiveness based on variables such as:

  • Age of the patient 

  • Health status of the patient 

  • What influenza viruses are circulating that season

  • Which type of flu vaccine was used

Reviews conducted by the CDC concluded that the flu vaccine is about 50% to 60% effective for adults between 18 and 64 years old who are healthy. 

While the vaccine cannot fully protect you from the influenza virus, it can decrease the severity of symptoms of the flu, and reduce the risk of complications or resulting in serious illnesses. 

What Are Other Things I Can Do to Prevent the Flu?

While the flu vaccine is the best thing you can do to prevent getting the flu, you can do some other things. These habits can help protect you from getting the flu along with other illnesses such as COVID-19. 

According to the CDC, precautions include:

  • Wash your hands often and thoroughly with soap and water for at least 20 seconds.

  • Use an alcohol-based sanitizer on your hands if soap and water are not available.

  • Avoid touching your eyes, nose, or mouth.

  • Avoid crowds when the flu is spreading in your area.

  • Avoid being in close contact with others who are sick.

  • Cover your mouth with a tissue or your elbow when you cough or sneeze, and then wash your hands.

  • Stay at home when you are sick.

  • Regularly clean and disinfect commonly touched surfaces, such as counters, light switches, or doorknobs. This can help to prevent the spread of infection from touching a surface with the virus on it and then your face.

  • Practice good health habits. Get regular exercise, get enough sleep, drink plenty of fluids, eat a healthy diet, and manage your stress.

How Much Does a Flu Shot Cost?

The flu shot cost ranges from $0 to $50 or more. The price depends on some factors such as:

  • If you have insurance. Most insurance companies will completely cover your flu shot cost, making it $0. 

  • Where you get your shot. If you do not have insurance, you can still get a very affordable flu shot. If you get your flu shot at a pharmacy or grocery store, they typically give you something in return, such as a gift card or coupon. 

  • What kind of vaccine you receive. A senior flu shot will typically cost more. 

  1. 1

    Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

  2. 2

    See a doctor, get treatment and a prescription at your local pharmacy.

  3. 3

    Use your health insurance just like you normally would to see your doctor.

Where Can You Get a Flu Shot?

You can get a flu shot at multiple locations such as: 

  • Your doctor's office

  • Community health departments

  • Urgent care

  • College health centers

  • Some schools

  • Flu clinics

  • Local pharmacies like CVS, Walgreens, and Walmart

To learn more about flu shots, you can consult your doctor. Book an appointment to speak with a board-certified doctor at PlushCare.


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