Get your tissues ready — flu season is coming.

The influenza (flu) virus typically makes its rounds starting in the late fall through early spring, which is why the Centers for Disease Control and Prevention (CDC) is beginning to get the word out that it’s time to start thinking about getting vaccinated.

Everyone six months of age and older, who does not have contraindications, needs to get a flu vaccine, according to the CDC’s 2019-2020 flu season recommendations.

While no vaccine can offer 100 percent immunity, when the viruses in the flu vaccine match the strains circulating in the population, “the flu vaccine has been shown to reduce the risk of having to go to the doctor with flu by 40 percent to 60 percent,” according to the CDC.

Here’s what you need to know about flu vaccination:

When to get the flu vaccine

The CDC recommends getting the vaccine by late October. However, infants and children ages 6 months through 8 years, who require two doses of the flu vaccine, should get their first shot as soon as possible so they can receive the second dose (which needs to be administered around four weeks later) by the end of October.

Sophia Tolliver, MD, family medicine physician at The Ohio State University Wexner Medical Center, tells Yahoo Lifestyle: “Per the CDC, flu activity can start as early as October/November and continue as late as May; peak flu activity is between December and February. The earlier the vaccination, the earlier the coverage and benefit against contracting the flu virus.”

That said, “You don’t want to get the flu shot too early, such as July or August,” Tolliver adds, “as protection could wane closer to the end of the flu season.”

But even if you do get the flu vaccine after October, it can still be beneficial. The CDC recommends getting vaccinated “as long as influenza viruses are circulating, even into January or later.”

How the flu vaccine works

It takes about two weeks after being vaccinated for the body’s immune response to kick in and offer protection from the flu virus. About two weeks after you’ve been vaccinated, antibodies — a protective protein made by your immune system — start to develop in your body. These antibodies are able to recognize the virus (known as an antigen) from the vaccine and can latch onto it and neutralize it.

Yes, you do need to get one every year.

Protection from the flu vaccine lasts about six months, according to the Immunization Action Coalition. That’s because the antibodies decline over time, making the vaccine less effective, and the specific flu virus that’s circulating in the population can change year-to-year. So you need an annual vaccination “to promote the body’s best immune response” against the flu, says Tolliver.

No, the vaccine doesn’t give you the flu.

For some reason, this myth continues to persist. That may be because some people experience mild reactions to the vaccine. While the most common ones are “soreness, redness, tenderness or swelling where the shot was given,” according to the CDC, some may experience a “low-grade fever, headache and muscle aches” soon after the shot, which can last for one or two days.

“What vaccinations essentially do is trigger the body into protecting itself in case the real thing — a virus/bug — comes around, so you may expect some level of a natural body response after receiving the flu shot,” explains Tolliver. “However, it is more likely that you were already brewing an infection even before the vaccination was given.”

She adds: “Also, the vaccination takes about two weeks to reach its full potential so in the interim if you are exposed to the flu virus, one might mistakenly blame a recent vaccination.”

It’s also worth noting that when you get a flu vaccine, you are either receiving flu viruses that are inactive (dead) and not infectious or else a single gene from a flu virus (rather than the full virus) to trigger an immune response, according to the CDC.

Why you don’t want to get the flu

The flu isn’t just a bad cold. It’s a serious disease — especially for infants, young children, adults ages 65 and older, and people with certain chronic health conditions, including asthma, heart disease, or diabetes — that can lead to hospitalization and even death, according to the CDC. Between October 2018 and May 2019, the CDC estimates that 36,000 to 61,000 people died from the flu.

“Vaccinations have been proven to save lives and additionally, decrease the severity and length of a potential infection,” says Tolliver.