The following column is the opinion and analysis of the writer.

It’s not just about you.

The U.S. could be headed for another bad influenza season based on the deadly season Australia had earlier this year. New information from the Centers for Disease Control and Prevention shows that California, Kentucky, Nevada and Louisiana already have flu activity.

The best time to get vaccinated is this month, and if you are on the fence about whether to get your shot, perhaps you can reconsider.

As a primary care physician, I often hear my patients say, “I never get a flu shot, because I never get the flu,” or “It’s not worth getting the flu shot because it’s rarely a good match for the right flu strain.”

A recent study by the National Foundation for Infectious Disease say fewer than half of U.S. adults typically receive an annual flu vaccination. The study shows the top reasons were “51% do not think flu vaccines work, 34% are concerned with side effects from the vaccine, and 22% are concerned about getting flu from the vaccine.”

Yet an individual’s action affects — or infects — the community.

“Herd immunity” or “community immunity” means that when more people in an area are vaccinated, fewer people overall get sick. Simply put, fewer germs are around to spread from person to person, and outbreaks can be contained.

This is particularly important when considering vulnerable populations, such as infants, people with lung conditions like asthma and COPD, those with cancer, and the elderly. These groups often do not have strong enough immune systems to fight off illnesses like the flu, and are at risk for complications such as pneumonia, heart or brain inflammation, and multiorgan failure.

If a young and otherwise healthy person gets the flu, they will likely be able to fight it off and get back on their feet after 7-10 days. But if that otherwise healthy person happens to come in contact with their newborn nephew or visits their grandmother in a nursing home while contagious with the flu, the consequences could be deadly.

Another myth at work is the belief that the flu vaccine can cause you to have the flu. The good news is the flu shot cannot give you the flu, since it’s made only with an inactivated virus. Usually, the only effects after getting the vaccine are mild redness and soreness at the injection site. Sometimes, a low-grade fever and muscle aches could occur, but usually are gone within 1-2 days.

That is a minor annoyance compared to the symptoms arriving with actual influenza, which usually comes on suddenly (unlike the common cold) and causes 1-2 weeks of symptoms such as fever, cough, runny nose, body aches, sore throat, severe fatigue, and sometimes vomiting and diarrhea.

If you get the flu, keep in mind that it’s contagious from at least a day before you begin to experience symptoms up through five days after your symptoms begin. This puts others at risk of catching the flu from you, even before you know you’re coming down with it. Simply planning to stay at home if you get sick isn’t enough to protect your community either.

To be sure, it’s true that flu vaccines are never a 100% match to the actual virus that circulates. However, a vaccine that’s 30% effective offers great value. Partial protection can still make symptoms less severe and result in fewer complications and hospitalizations, even if you do get the flu.

The CDC recommends that everyone over 6 months of age get vaccinated, ideally by the end of this month.

Consider that getting a flu vaccine can be your good deed for the day (or the season), and help protect your co-workers, neighbors and family members, who may not be able to protect themselves.

Lisa Ravindra is a primary care physician and an assistant professor of Internal Medicine at Rush University Medical Center in Chicago. She is a Public Voices Fellow through The OpEd Project.