Everyday Health

6 Myths About the Flu Shot

Originally published November 7, 2016

Last reviewed January 5, 2022

Reading Time: 4 minutes

Flu season has officially started, but not everyone has been vaccinated yet. We share the facts behind some of the most common misconceptions about the flu shot.

There are just as many myths, half-truths and questions swirling around about the flu vaccine as there are people infected with the virus. Protect yourself from influenza by getting vaccinated and understanding why it’s an important component in your overall well-being.

Myth #1: The flu shot makes you sick.

This is probably the most common and widely spread myth about the flu shot out there, so if this is your concern, you’re in good company. However, the flu shot definitely does not make you sick. It’s made from inactivated flu viruses, which are present in the vaccine but are not infectious, or proteins from a flu virus. The vaccine causes antibodies that protect against the influenza virus to develop about two weeks after the vaccination.

“When people say they get ‘sick’ after a flu shot, it’s more likely they got a respiratory virus that is also floating around in the community at the same time that flu vaccines are being given,” says Anjali Mahoney, MD, MPH, a family medicine specialist at Keck Medicine of USC and clinical associate professor of family medicine at the Keck School of Medicine of USC.

“Even though some people may experience a low-grade fever, chills, cough and a runny nose after getting a flu shot, it’s important to know that influenza is a more serious illness that can often land patients in the hospital. The flu shot prevents you from getting influenza by preparing your immune system for the virus,” she adds.

Myth #2: It’s not effective.

Figuring out the exact three or four strains to vaccinate against does involve some guesswork, and the scientists don’t always get it right. So, it is possible to get the flu shot and still get the flu. The Centers for Disease Control and Prevention (CDC) estimated that the flu shot for the 2019-2020 season was about 39% effective. Still, the shot is your best defense against the flu, and if you do get it, chances are it will be a milder case and last for a shorter amount of time than if you didn’t get the shot.

Myth #3: The flu shot is only for kids and elderly people.

It is especially important for children and other groups of people with weaker immune systems, including the elderly and pregnant women, to get the flu shot. Studies have shown that children who had the flu shot were 74% less likely to be hospitalized for the flu. People aged 50 and older reduced their risk of hospitalization from the flu by 40% when they got the flu shot. The CDC recommends everyone 6 months and older get a flu shot, with rare exceptions.

“Getting a flu shot will protect you and those you love from influenza. There is a phenomenon called herd immunity, where the more people are vaccinated, the less likely a disease is to spread within a community. If more people get their flu shot, it helps protect everyone,” Mahoney explains.

Myth #4: If you don’t like needles, you can get the flu nasal spray.

While the live attenuated influenza vaccine, also known as the nasal spray flu vaccine, is available, it is not recommended for everyone, and its effectiveness can vary from season to season. The CDC has a list of who should not be vaccinated with the nasal spray flu vaccine, and it provides yearly updates on the effectiveness of this option, during the current flu season.

Myth #5: If you’re allergic to eggs, you can’t get the flu shot.

While that was true in the past, the current CDC recommendations are that you can get the flu shot, with one caveat. If you get light-headed or have breathing problems after eating eggs, you should get the shot at your doctor’s office or a medical clinic. If you get hives and don’t have other symptoms, it’s okay to get the flu shot in any setting, including your office (if your employer offers it) or at a drugstore. In some cases, an eggless flu shot is available.

Myth #6: It’s too late to get the flu shot.

It takes two weeks for the effectiveness of the flu shot to kick in, and in the past, the flu season has lasted all the way through May. “The sooner you get the flu shot, the sooner you protect yourself and those you love,” Mahoney says.


Dr. Anjali Mahoney
flu season
flu vaccine
Anne Fritz
Anne Fritz is a freelance health and lifestyle writer.