Flu Shots 101: Who Needs a Flu Shot and When Should I Get One?

Haley Bass

There’s no question that flu season is coming – every year, starting in the fall, there are notices everywhere about getting vaccinated and washing your hands regularly. But year after year, people still have the same questions about the flu vaccine.

We want to answer all your basic flu questions so you feel more confident heading into flu season. In this flu shots 101 guide, learn who needs a flu shot and when to get one.

When is flu season?

We recommend getting a flu vaccine at the start of the flu season in September. However, getting a flu shot later in the season can still provide benefits, as the Centers for Disease Control and Prevention (CDC) states that the flu season in the U.S. typically peaks between late December and early March. In some years, significant flu activity can last until May. 

Who should get a flu shot?

The CDC recommends that anyone six months of age or older should get an annual flu shot, including pregnant women. With a flu shot, pregnant women can protect themselves and their developing babies, even in the first few months after birth.

The exceptions are people who have severe allergies to eggs or vaccine ingredients, or those who have had Guillain-Barré syndrome, a rare disorder in which the immune system attacks nerve cells. In these cases, the CDC asks you to talk to a doctor before getting a flu shot.

How long does a flu shot last?

This question is a little tricky. Because the flu season is unpredictable and everyone’s immune system may respond differently to a flu shot, there’s no way to put a specific timestamp on how long the effects of your flu shot will last. On average, a flu shot provides protection against the specific flu strains it was designed to treat for up to nine months. The CDC notes that while “delaying vaccination might permit greater immunity later in the season, deferral could result in missed opportunities to vaccinate.” Vaccination in the fall ensures that the impact of the vaccine with last through the flu’s most active months.

Regardless of what part of the season you get your flu shot, the CDC does say that you need to get a new one every year. This is for two reasons:

  1. The vaccine’s immunity declines over time, so it needs a refresher every year.
  2. The flu virus is constantly changing, so the strain your shot protected you against last year may not be the strain that physicians are concerned about this year.

How long does it take for a flu shot to work?

It takes about two weeks for the flu shot to take effect. The antibodies that protect you against infection need that time to develop in your body. After you get your flu shot, make sure to continue taking precautions against the flu: wash your hands regularly, cover your mouth when you cough and sneeze, and avoid touching your eyes, nose, or mouth.

With more than 520 locations across the country, there’s likely a Concentra® center near you, and we offer flu shots at every one of them! No appointment required. Find your nearest Concentra center and get the protection you need against the flu.