The flu makes us feel terrible, we already know that. From sore throats to stuffy noses, to headaches, coughs, body aches, and fevers, influenza is a virus that can knock you out of commission for days, a week, even two weeks. It’s also a scary, and annoying, false alarm for COVID. Fortunately, there is evidence-backed protection against this highly contagious, potentially very serious virus: an annual flu vaccine. But despite the undeniability of the flu shot’s effectiveness, every flu season people come up with reasons not to get vaccinated. Some worry “can the flu shot make you sick?” or “can you get a flu shot while pregnant?” Others don’t trust the flu shot’s effectiveness or worry about flu shot ingredients. In any case, it can be hard to kick the paranoia. But those myths are all just that — myths — and they’re patently untrue. When it comes to the pros and cons of getting a flu vaccine, the pros are many and the cons are few.
Every year, the flu vaccine contains deactivated particles from the four strains of influenza most likely to be prevalent that coming flu season. It is these strains that determine the flu shot‘s effectiveness. Once those are injected into a person’s body, the immune system generates antibodies that fend off the flu should they be exposed to it. Although no vaccine will protect you 100%, the flu shot can make influenza far less devastating to your body if you do get sick.
Despite the proven effectiveness of the flu vaccine, only about half of the nation gets immunized each year. And because last year’s flu season was mild with people wearing masks and social distancing to protect against COVID, experts believe that the flu could come back with a vengeance this year as people take less precautions. The “twindemic” of both the flu and COVID could be an extremely deadly mix. That’s all the more reason to get both your flu vaccine and your COVID shot.
A handful of mistruths and misconceptions about the flu vaccine is partly to blame for too-low vaccination rates. Here are popular reasons not to get the flu shot, dismantled by science, one by one.
Myth #1: The Flu Shot Doesn’t Work
Plenty of research shows that the flu vaccine, while not perfect, does indeed work. According to the Centers for Disease Control and Prevention (CDC), when the vaccine is well-matched against the viruses circulating that year, it slashes the risk of flu illness between 40% and 60%.
Typically, when people claim the flu shot isn’t effective or try to argue why you shouldn’t get a flu shot, it’s because they or someone they know got the flu shot but still got sick. The CDC offers up a few explanations for this. For one, they may have been sickened by a different virus, such as rhinovirus, which can cause flu-like symptoms. Or, if they really did get the flu, it’s likely because they were exposed to the virus shortly before being vaccinated or during the two weeks post-vaccination that are required for the body to build up immunity. Another possibility is they contracted an influenza strain other than those included in the vaccine.
There is also a small chance of getting the flu even when the vaccine is a close match. “I wish we could create a vaccine to eradicate this virus forever, but the problem is we’re dealing with a very sophisticated organism that is constantly mutating,” says Eduardo Lopez, MD, head of the nephrology department at Kaiser Permanente’s Panorama City Medical Center in California. “We try to prepare a cocktail of different antigens every year based on data, and even though it may not be a perfect match, you’re better off getting vaccinated.”
Myth #2: The Body Can Defend Itself Against Influenza
“One of the most common myths I hear is that we’ve all been exposed to the virus, so the body can create a natural immune response to defend itself,” Lopez says. “Yes, our bodies have a natural immune response, but it’s not necessarily enough to protect you from serious illness.” The vaccine, however, prompts the body to produce additional antibodies, giving you a much better protective barrier against illness.
Myth #3: Healthy People Don’t Die From the Flu
Although it is true that people with underlying health conditions such as asthma, heart disease, diabetes, or cancer have a greater risk of flu-related complications and death, plenty of otherwise healthy adults and children wind up in the hospital from influenza. Some even die from the disease, making arguments against the flu vaccine thin on this ground.
But let’s assume for a second that you have only mild symptoms, or you’re among the 20 to 30 percent of flu carriers who have no symptoms at all. Even so, you can spread influenza to others who may not be so lucky — they could become extremely ill or even die. The best way to protect yourself and those around you is clear: Get an annual flu vaccine.
Myth #4: The Flu Vaccine Contains Harmful Chemicals
For many years now, a small segment of vaccine detractors — known as anti-vaxxers — have been trumpeting the myth that certain ingredients in the flu shot are toxic and cause health complications. They usually blame formaldehyde, used to deactivate the virus in the vaccine, and thimerosal, an ethylmercury-based preservative. These ingredients have been deemed safe by the Food and Drug Administration. And, according to a large body of evidence, they aren’t linked to any disorder.
Myth #5: The Flu Vaccine Can Make You Sick
Although some people claim to have gotten the flu from the flu shot, Lopez says this is impossible. “The flu shot cannot give you the flu because it is made out of killed vaccine particles that cannot cause disease,” he says.
The flu shot can produce mild side effects, which some people wrongly assume is the flu. “It is possible to feel run down,” Lopez says. “There can be localized pain at the injection site, body aches, congestion, or even a low-grade fever. This is because the body is mounting an immune response to stimulate what was just inoculated, but it’s not the actual flu.” Nor is it nearly as miserable. Lopez says a dose of Tylenol or ibuprofen should help ease these symptoms in short order.
“Many people wait until flu season is raging, in December or January, to get vaccinated, and they may have already been exposed to the virus,” Lopez says. “If they’d gotten the vaccine in August when it first becomes available, there’s a very good chance they would not have gotten sick.”
Myth #6: Pregnant People Shouldn’t Get the Flu Vaccine
The flu shot is not connected to miscarriage, as some people falsely assume. In fact, the influenza virus — not its vaccine — is what’s linked to miscarriage and other potential problems for a pregnant person and their unborn child. According to the CDC, millions of pregnant people have gotten vaccinated safely, and a large body of evidence supports the shot’s safety.
For this reason, except in rare cases when the pregnant person has a severe, life-threatening allergy to a component of the vaccine, experts strongly recommend they get a flu shot. Besides protecting the parent and the developing fetus from the virus, the immune defenses from vaccination will continue to safeguard the baby once they’re born. This coverage will last until the child is six months old and can receive their own flu vaccine.
Myth #7: You Don’t Need a Flu Shot Every Year
“Sometimes patients get the flu shot in February then come into my office in September and say they don’t need another vaccine because they got it in February,” Lopez says. “I tell them this is a different flu season, so they need it again.”
In these cases, people are assuming that their bodies will still have enough immune protection to carry them through another flu season unscathed. However, even when the influenza strains targeted by a new vaccine are the same as those included in the previous season’s shot, immune protection declines over time. Whatever defense you have leftover from last flu season may not be enough to stop you from getting sick this go-around.
“When we look at individuals who get the flu shot every year versus those who skip years, there is proof that it is beneficial to get vaccinated every single year,” Lopez says.