As crisp fall weather rolls in, there’s another change in the air. The flu.

Influenza causes millions of illnesses in the United States every year. But annual flu shots also help prevent millions from getting sick – and that’s a fact.

According to the Centers for Disease Control and Prevention, (CDC), 2019-2020 flu vaccinations helped prevent an estimated 7.5 million illnesses – plus, thousands of hospitalizations and deaths.

But there’s a lot of misinformation floating around out there. New and scary flu shot myths spread quickly, just like the flu does.

That’s why I care so deeply about separating flu shot myth from flu shot fact. I think we can all agree keeping ourselves – and our community – healthy during the long flu season should be a top priority. And getting your flu shot is the best way to make that happen.

So, let’s take a look at some of the most common flu myths versus the facts you need to know.

Myth #1: You can get the flu from the flu shot

Fact: The flu shot does not contain an active virus. So, the answer to the question like “Can you get the flu from the flu shot?” is a no.

But for some, the flu shot does come with mild side effects that can easily be mistaken for early flu-like symptoms. The most common include mild soreness, tenderness or a bit of swelling at the injection site. You may also run a small fever, or experience slight headaches or muscle aches.

On the other hand, many experience no side effects at all! Plus, a day or two of mild discomfort simply doesn’t compare to what you can experience with a full bout of the flu. Flu symptom onset is fast and often involves fever, chills, extreme fatigue, muscle aches and more for several days.

Are you “contagious” after a flu shot if you experience side effects?

The mild symptoms you might experience after getting vaccinated are an immune response, not the signs of an illness. That’s because even though the flu vaccine contains inactive virus, your immune system still recognizes it as an intruder and creates antibodies. This antibody creation is what can spur side effects, as well as get your body ready for a possible exposure to an active virus.

Myth #2: You don’t need to get a flu shot every year

Fact: There are a lot of influenza viruses out there. And every year, the CDC and the World Health Organization (WHO) perform rigorous testing to determine which strains of influenza pose the highest threats globally.

So, one of the most important things you should know about the flu vaccine is that it too changes every year, based on this research. Which means that even if you had your shot last year, you’ll need one this year as well.

How long is the flu shot good for?

The flu shot is effective for about six months, which is about the length of flu season.

Myth #3: Waiting until winter for a flu shot is safer

Fact: While peak flu season is between December and February, you can get sick as early as October. Some believe that getting vaccinated later will protect them longer, which is simply false. This also leaves you exposed for weeks, or months while the virus is floating around.

Also, an annual flu shot helps your body build immunity for the types of influenza viruses that research indicates will be the most common that season. But immunity isn’t built as soon as you get the shot. How long does it take for the flu shot to take effect? Two weeks – which is another reason to schedule your flu shot early.

While getting your flu shot as soon as the vaccine is available offers the best protection, the CDC recommends everyone 6 months and older get vaccinated by the end of October. Pregnant women – particularly those in their third trimester – should receive a flu shot as soon as the vaccine becomes available.

When is it too late to get a flu shot?

Flu shots are typically available by early September – well before the traditional flu season begins – through March. But it’s never too late to get your shot – even in January. Influenza season can often last well into May. Late protection is better than no protection at all!

Myth #4: I don’t need the vaccine, I never get the flu

Fact: Unfortunately, a flu-free history does not guarantee a flu-free future. Flu strains evolve and change over time, which means you are at risk every year you avoid getting vaccinated. In addition, when you skip your shot you can still carry and pass flu germs to others.

Influenza symptoms can leave us stuck in bed for days using up valuable vacation time. I always ask patients, why not save up those days for a sunny vacation instead?

Myth #5: Flu shots don’t work

Fact: The flu vaccine can significantly reduce your risk of catching the flu.

In previous years, when the vaccine matched circulating strains, the CDC reports that getting vaccinated reduced the chance of catching the flu by up to 60%.

Flu vaccination also significantly reduces the risk of flu-related hospitalization for the elderly, working age adults, and especially among children. A 2014 study showed that the flu vaccine reduced children’s risks of flu-related pediatric intensive care unit admissions by 74%. And the vaccine could even be a life-saver – a 2017 study showed that flu vaccinations reduce a child’s risks of dying from the flu.

Flu shots are important for pregnant women, too. Since pregnancy affects your immune system, it can make you more susceptible to the flu. Getting a flu shot while you’re pregnant is safe for both mom and baby. Plus, it can help protect the baby after they’re born until they can have their first flu shot.

When more people choose to vaccinate, doctors and CDC researchers are better equipped to pinpoint flu strains, keep rates of hospitalization down, and keep you and your family protected. Also, the science of vaccinations improves every year, and so do your odds of staying healthy with a flu shot.

Myth #6: Catching the flu builds your immunity more than the vaccine

Fact: Having heard that the flu shot doesn’t always work, some are led to believe that getting the flu will boost your immunity more than the flu shot.

There’s no truth to this claim. And sitting around waiting for the flu to strike is certainly not a good idea.

The flu can get serious fast, especially in children and older adults. But it also carries risks of complications for healthy people. Getting vaccinated is much safer, and comes with the same immunity benefits. And no, the flu shot doesn’t weaken your immune system. Rather, it’s the opposite. The immune response the flu shot triggers helps get your body ready if you’re exposed to the active virus.

While protecting you, the flu shot also protects loved ones around you from getting sick. Once your body builds immunity – which takes two weeks – you can’t pass flu germs to anyone else. Now that’s something you can feel good about.

Be a flu fighter by getting your annual flu shot

There are a lot of reasons to get a flu shot. It’s fast. It’s easy. It’s almost always free. But maybe one of the most important reasons is that it can significantly reduce your risk of getting the flu and passing it to others. And this helps you, your family and community stay healthy, happy and productive.