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8 Things You Do That Might Be Messing Up Your Flu Shot

Read this before you roll up your sleeve.

Yes, you should get your flu shot

If you’re dreading this year’s flu shot—we don’t blame you. No one wants to subject him or herself to a needle injection that doesn’t always seem mandatory. But while flu shots might not be required, they are strongly encouraged by the medical community—for good reason. The flu is a serious disease that can lead to pneumonia, hospitalizations, and death, says Margaret Khoury, MD, pediatric infectious disease specialist and regional lead of the Kaiser Permanente Southern California Flu Vaccination Program. 

Each year, health experts around the world determine which flu strains are most likely to be the worst in the upcoming year. They use that information to target the flu shot to make it more effective—exactly how effective it depends on how good their predictions were, and some years are better than others. The flu shot is either “trivalent” or “quadrivalent,” which means it protects against the three or four strains of influenza and even if they only get one or two strains correct it’s still worthwhile to get the shot, she explains.

This is because it works: Getting a flu vaccine reduces your risk of getting the flu by 40 to 60 percent and can lessen the severity of the illness if you do end up getting sick, according to the Centers for Disease Control. 

While the only real way to mess up your flu shot is to not get it at all, we asked top experts to reveal the biggest misconceptions and mistakes people make when it comes to getting a flu vaccine. Here are secrets the flu virus doesn’t want you to know.

African American doctor giving a man his flu shotiStock/Steve Debenport

You skip this year’s flu shot because you got one last year

Every year influenza viruses mutate—the virus isn’t the same as the one you were vaccinated for last year. “People need to get the flu shot every year because flu viruses are constantly changing and it is not unusual for new flu viruses to appear each year,” says Caroline Sullivan, nurse practitioner, primary care provider, and assistant professor of nursing at Columbia University in New York. “Studies have shown that the body’s immunity to influenza either through natural infection or vaccination declines over time.” If you got the vaccine last year and still came down with the flu, it’s natural to wonder why you’d get the flu vaccine again, but experts say that in these scenarios, the virus has mutated so the vaccine hasn’t kept up, or the illness you might have had was not true influenza, but another virus altogether. Check out these 9 natural remedies to help you kick the flu.

Asian woman sneezing into a tissueiStock/andresr

You avoid the vaccine because you suspect you already got the flu

Are you sure it was the flu and not some other virus? Positive? Not only can you not be sure you’ve had it (unless you were tested) but there are multiple strains of influenza circulating every year, so getting one strain doesn’t protect you from the others, Dr. Khoury says. As a bonus, even if you are sick, the flu shot can lessen the severity of your illness and protects you from other viruses through cross-protection antibodies, she says. These are viruses that are similar to the strains of flu in the flu vaccine, which your body learns to fight off. Here’s what to eat if you have the flu.

woman outdoors holding her armistock/Mixmike

You think the flu vaccine will actually give you the flu

This is the most common misconception people have about the flu shot but science doesn’t back it up. The flu shot is made in such a way that it either contains no flu virus at all, or an inactivated or noninfectious virus, says Dr. Khoury. So while the flu vaccine may cause a low-grade fever and muscle aches in some people, these symptoms are usually temporary and are not actually an influenza infection. You should also make sure you know these 10 myths about vaccinations you can safely ignore.

African American young man looking warily at a syringe in a doctor's handsistock/Juanmonino

You make the flu vaccine hurt even more than it should by tensing up

Fear of needles is a very common reason people avoid the flu shot but there are ways to help you deal with this, says Amy Baxter, MD, founder and CEO of MMJ Labs. “I do the scientific research on why, but the important thing is once someone is afraid, they tend to keep that fear for life,” she says. But you could be in control of how painful the vaccination experience is for you. First: Try not to tense up. “Tensing a muscle makes it hurt more, so try to relax the arm and focus on breathing,” says Baxter. “There are many strategies to reduce needle fear, but it usually takes three good experiences to help someone overcome it.”

people doing deadlifts at a gymiStock/gradyreese

You don’t exercise the day of your flu shot

Working out before or after you get jabbed may help your body churn out more flu-fighting antibodies, according to a small study done by Iowa State University. Students who jogged or biked for 90 minutes after they got the flu shot had nearly double the number of antibodies of students who didn’t. And you don’t have to be a regular exerciser to get the benefit — even just one workout helped, they found. Here’s how to figure out whether you should still work out when you’re sick.

doctor discussing treatment with a patientistock/knape

You wait too long to get the vaccine

 A typical flu season in North America starts as early as October and continues into May and the flu shot works best when it is given earlier in the season, Dr. Khoury says. The CDC recommends getting the flu shot as soon as it is available, which is why most doctor’s offices and pharmacies start giving out the vaccine as early as September. The earlier a person is vaccinated, the more antibodies and immunity they can develop before the height of flu season, which is January and February, she explains. Since it takes about two weeks to build up immunity after you receive the vaccine, it’s best to schedule your flu shot in early fall. But if you find yourself unvaccinated in late January or February, it’s still recommended to get the flu vaccine.

pregnant woman holding a teddy beariStock/vgajic

You don’t get the flu vaccine because you’re pregnant or breastfeeding

This is a hot topic among pregnant and breastfeeding women, as well as those trying to conceive, but the verdict is in: You should absolutely get vaccinated. “Pregnant women should definitely get a flu vaccine, as they’re one of the most susceptible populations and can become seriously ill and even die from the flu,” says Laura Haynes, PhD, a professor in the department of immunology at the University of Connecticut. Plus, if you’re breastfeeding an infant and have received the vaccine during your pregnancy, then you pass all of the immunity you acquired from the vaccine onto your newborn or infant — this is called passive immunity, and another amazing benefit of breastfeeding, she explains.

woman doctor giving an elderly man a shotiStock/Catherine Yeulet

You don’t get the vaccine because you think you’re too old—or young

Anyone older than six months should get the flu vaccine (unless you have a medical reason to avoid it, like an allergy or an immune disorder), Dr. Khoury says. This is especially important for children older than six months or anyone who cares for children, the elderly or their caregivers, pregnant women, people with asthma, heart disease, or diabetes; anyone over age 50; anyone who suffers from an autoimmune disease; anyone who lives in a nursing home or long-term care facility; those with obesity; and all healthcare workers, she says. That pretty much means all of us. However, if you’re over the age of 65, wait until at least late October to get your vaccine (between Halloween and Thanksgiving). This is because the vaccine’s protection wanes more quickly in older individuals. If they get the vaccine too soon, protection might not last the entire flu season. (But if the only choice for some seniors is to get the vaccine earlier or not at all, they should choose to get it earlier.) Don’t miss these 40 things your doctor wishes you knew about vaccines.

  • Kathleen Cameron, MPH, senior director, Center for Healthy Aging, National Council on Aging (NCOA
  • Caroline Sullivan, nurse practitioner, primary care provider, and assistant professor of nursing at Columbia University
  • Margaret Khoury, MD, pediatric infectious disease specialist and regional lead of the Kaiser Permanente Southern California Flu Vaccination Program
  • Amy Baxter, MD, founder and CEO of MMJ Labs
  • Iowa State University: “Iowa State researchers studying impact of exercise on flu vaccine resistance in adults”
  • Laura Haynes, PhD, professor in the department of immunology at the University of Connecticut
  • Centers for Disease Control and Prevention: “Vaccine Effectiveness: How Well Do the Flu Vaccines Work?”  
Medically reviewed by Michael Spertus, MD, on October 22, 2019

Jenn Sinrich
Jenn Sinrich is an experienced digital and social editor in New York City. She's written for several publications including SELF, Women's Health, Fitness, Parents, American Baby, Ladies' Home Journal, and more. She covers topics from health, fitness, and food to pregnancy and parenting. In addition to writing, Jenn volunteers with Ed2010, serving as the deputy director to Ed's Buddy System, a program that pairs recent graduates with young editors to give them a guide to the publishing industry and to navigating New York. When she's not busy writing, editing, or reading, she's enjoying and discovering the city she's always dreamed of living in with her fiancé, Dan, and two feline friends, Janis and Jimi.