The flu makes us feel terrible, we already know that. From sore throats to stuffy noses, to headaches, coughs, body aches, and fevers, the flu is a virus that can knock you out of commission for days, a week, even two weeks. Fortunately, there is evidence-backed protection against this highly contagious, potentially very serious virus: an annual flu vaccine. The flu vaccine saves lives, but despite the undeniable flu shot effectiveness, every year, people come up with reasons not to get the flu shot. Whether it’s flu shot myths that have turned you off from your annual dose, such as the flu shot making you sick, uncomfortable flu shot side-effects, “mercury,” whether you can take the flu shot while pregnant, or just overall questions of flue shot effectiveness, it can be hard to kick the paranoia. But those myths are all just that — myths — and they’re patently untrue.
The truth is, every year the flu shot 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 effectiveness. Once those are injected into the body, the immune system generates antibodies that fend off the flu should you be exposed to it. While no vaccine will protect you 100 percent, the flu shot can make the flu far less devastating to your body if you do get sick.
Despite the proven flu-shot effectiveness, only about half of the nation gets immunized each year. And in a year with the COVID-19 pandemic, experts believe the “twindemic” of both the flu and COVID-19 could lead to an extremely deadly mix. A handful of mistruths and conceptions about the flu shot 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 vaccine, while not perfect, does indeed work. According to the CDC, when the vaccine is well-matched against the viruses circulating that year, it slashes the risk of flu illness between 40 percent and 60 percent.
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, M.D., 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,” says Lopez. “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: You don’t need a flu shot every single 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, the immune protection declines over time. Therefore, 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.
Myth #4: 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 the ground.
But let’s just assume for a second that you have only mild symptoms or you’re among the 20 percent to 30 percent of flu carriers who have no symptoms at all. Even so, you can still 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 shot.
Myth #5: 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 may 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 FDA, and, according to a large body of evidence, none are linked to any disorder.
Myth #6: The flu shot can give you the flu
While some people claim to have gotten the flu because of 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 some mild side effects, which some people quickly — and 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 is 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.
“Also, 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 #7: Pregnant women shouldn’t get vaccinated
The flu shot is not, in fact, 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 mother and unborn child. According to the CDC, millions of pregnant women have received the vaccine safely, and a large body of evidence supports its safety. For this reason, except in rare cases when the mother has a severe, life-threatening allergy to a component of the vaccine, all pregnant women are strongly encouraged to get a flu shot. Besides protecting the mother and her developing fetus from the virus, the immune defenses from vaccination will continue to safeguard the baby once they are born. This coverage will last until the child is six months old and can receive their own flu vaccine.