Flu Vaccine FAQ: Fact or Fiction?

A nurse gives a patient an injection in the arm.

As we enter the fall months, the flu season is upon us.

While the 2020-2021 flu season was unusually quiet—primarily due to increased masking, remote learning, and remote work—we expect the 2021-2022 flu season to be similar to past flu seasons.

During the 2019-2020 flu season, there were an estimated 24,000-62,000 flu deaths in the U.S., according to the Centers for Disease Control and Prevention (CDC).

As COVID-19 measures become less strict in certain states and municipalities, it is especially critical to receive your flu shot to help avoid serious illness.

The flu vaccine has demonstrated effectiveness in preventing and reducing complications of the flu.

Tom Sequist, M.D.
Chief Patient Experience and Equity Officer

Below are seven myths about the flu vaccine with the facts to help you understand why it is so important.

Myth 1: “The last time I got the flu shot, it gave me the flu.”

Fact: The flu shot cannot cause the flu. Flu shots either contain inactivated (“killed”) flu virus or parts of the virus.

A small percentage of people do have a mild reaction to the flu shot such as headache and muscle aches (or your arm may be sore around the shot itself). This is your body’s reaction to the flu shot, and it is not an actual infection.

Myth 2: “I heard the flu shot didn’t even work last year.”

Fact: Historically, the effectiveness of the flu shot last year is between 40-60%. That means it decreases the percentage of people seeking care for flu-like illness by 40-60%. That’s more effective than medications we use to treat many common illnesses.

You can still get the flu even if you are vaccinated. However, if you received the vaccine, we know that your flu infection and symptoms are more likely to be less severe.

Myth 3: “I would rather just get the flu, it’s not that bad.”

Fact: The flu is a deadly illness. Don’t confuse this with the “common cold,” which is a completely different virus. Historically, the flu causes approximately 50,000 deaths per year in the U.S. It also accounts for more than 16 million doctor, emergency department, and hospital visits per year, which can put a strain onto our health care system.

Myth 4: “I never get the flu, so I don’t need the flu shot.”

Fact: This is just the luck of the draw. You are probably not immune to the flu without a vaccine. When you get the flu shot, you are not just protecting yourself. You are also protecting others around you by preventing the spread of the flu, including our patients, your family, and your friends. You may have heard the phrase “herd immunity,” which means that if everyone is immune, the flu virus cannot spread (“the herd is safe”).

Flu vaccinations are important as we continue to deal with the pandemic of COVID-19. The flu vaccine can help avoid adding additional strain onto the medical system.

Myth 5: “I got the flu vaccine last year, so I don’t need it again this year.”

Fact: Unfortunately, the immunity from the flu vaccine can wear off. In addition, the flu viruses circulating change from year to year, so you need to receive an annual flu shot.

Myth 6: “I don’t want to get my shot too early. I want to wait until later in the winter, so it lasts.”

Fact: While the peak of flu infections is between December and February, and the flu circulates in our area between October and April. The CDC recommends everyone to be vaccinated against the flu by October, since it can take a few weeks for the immune system to build up resistance. If you wait to get the flu shot, you will be less likely to fight off the flu.

Myth 7: “I have an allergy to the flu shot, so I cannot receive it.”

Fact: True medical allergies to the flu shot are rare. The CDC advises that a small group of people should not get the flu vaccine. You should not get a flu shot if you have a severe, life-threatening allergy to any ingredient in the flu vaccine (other than egg proteins), such as gelatin, antibiotics, or other ingredients.

You should talk to your doctor before getting a flu shot if you:

  • Have an allergy to eggs or any of the ingredients in the vaccine. Egg allergy is not a contraindication to receiving the flu shot. The CDC provides guidance related to egg allergies and the flu shots.
  • Have a history of Guillain-Barre Syndrome (GBS). Some people with a history of GBS should not get the flu vaccine.
  • Have had a severe allergic reaction to a previous dose of any other flu vaccine
  • Are not feeling well. Talk to your doctor about your symptoms as you may need to wait until you recover to get your vaccine.

The CDC offers additional guidance about who should and should not receive the flu shot.

You can get your flu shot at your local pharmacy, at a nearby community health center, or at a Mass General Brigham location. You can find answers to additional questions about the flu vaccine on the CDC’s website.

Flu Vaccines at Mass General Brigham