The flu is a highly contagious respiratory condition that travels via airborne droplets from sneezing or coughing. While most cases improve in 1-2 weeks, serious complications can occur in adults over 65.

The Centers for Disease Control and Prevention (CDC) estimates nearly 500,000 people are hospitalized each year from influenza-related complications. Every year, the variant of influenza changes. The best way to protect yourself against it is by getting vaccinated for the type of flu that’s expected in the coming winter. 

But there’s an optimal time to get this protection against this unwelcome winter visitor. This article lays out when.

Flu Basics

There are two main types of flu viruses, influenza A and influenza B. It’s estimated that the A strain causes 75% of yearly infections. The symptoms are much more prolonged and severe than a cold. The infection stresses the body’s immune system and makes it more susceptible to potentially fatal complications such as pneumonia. 

Annual vaccination prevents around half the infections in a typical flu season. For those who still become sick even with the vaccination, the shot may reduce severe symptoms. It also helps lower the spread of the virus by reducing the time someone can spread infectious droplets.

When’s the Best Time to Get a Flu Shot? 

The CDC recommends that the best time to get vaccinated is from the start of September to late October.

Flu is most common during the fall and winter months as we tend to spend more time inside. This increased contact with other people in more humid temperatures increases the rate of spread. Getting your shot before it gets too cold and before the flu rates climb is your best way of avoiding illness.

Another reason for the early shot is that your body needs two weeks to develop a protective response. Conversely, the level of protection from your immune system decreases over time, so receiving a flu shot before September could make you more vulnerable as winter passes.

Who Should Have It

Flu vaccines encourage your immune system to produce a small number of antibodies. If you then encounter the flu throughout the winter, these established antibodies attack and kill the virus, stopping it from becoming severe.

The CDC recommends an annual flu shot for everyone 6 months and older. Vaccination is particularly important for people at high risk of complications, including young children, older adults, and pregnant women. The vaccine is safe for most people, with the exception of those who have a severe allergy to any of its ingredients.

The vaccine is also available as a nasal spray. The spray is safe for those between 2 and 49 years old but isn’t recommended for certain people, including:

  • Children between 2 and 17 years who take aspirin
  • Adults age 50 and older
  • Pregnant women
  • People with weakened immune systems

Side Effects of the Flu Vaccine

There’s a small risk of side effects with the flu vaccine, the most common being tenderness at the injection site. Some people also may experience cold-like symptoms for 1 to 2 days after.

Serious reactions are rare, but you might have issues if you’re severely allergic to an ingredient in the vaccine. If you have any of the following symptoms, seek immediate medical attention:

  • Difficulty breathing
  • Nausea
  • Hives
  • Excessive dizziness

The Takeaway

People medically fit and over the age of 6 months should get a flu vaccine each year in order to be protected. The best time to get your shot is from early September to late October. This timing gives maximum protection for the duration of the flu season.

Flu vaccines are usually available at your doctor’s office, a local pharmacy, or a walk-in clinic. It’s often free if you have health insurance; even without insurance, you should be able to find one for under $50. Employers may also provide vaccines for employees at their workplace.

Talk with your doctor to see which flu vaccine is right for you, and get vaccinated as early as possible.