October means not only cooler temperatures, the end of the Jewish holiday season, the start of the Braves’ long offseason and the rise of Georgia-Florida football excitement, but also the arrival of flu shot season.

According to the Centers for Disease Control and Prevention, everyone over the age of 6 months should get a flu shot by the end of the month. Doctors’ offices, drugstores and Grady Memorial Hospital, among other health care facilities, have the vaccine ready for the public, said Dr. Jason Schneider, an associate professor at Emory University’s School of Medicine who works in general medicine at Grady.

Dr. Jason Schneider says a flu shot is the best way to protect yourself and others.

Dr. Jason Schneider says a flu shot is the best way to protect yourself and others.

“It’s important to emphasize that a flu shot is the single best way to protect yourself and friends and loved ones from the flu,” Schneider said during an interview about the 2015-16 flu season.

The flu vaccine could be a harder sell than usual this year because of the poor results last year. The vaccine’s composition badly missed the mark, blocking only 19 percent of the U.S. flu cases, one of the lowest matches Schneider can remember.

“Last year was a pretty rough year,” he said. He explained that the CDC usually succeeds in planning the shot’s makeup based on flu activity in the Southern Hemisphere, but the genetics of the viruses can change quickly.

The hope is that the vaccine is more effective this year, but even if it’s not, Schneider said, it’s worth getting the shot. After all, if mutating viruses make the vaccine effective against only 20 percent of the flu cases, that’s still one in five potential cases of the flu that are avoided. If you don’t get a flu shot, you’re protected against none of the flu viruses.

“If it were a riskier proposition, it would be a different discussion,” Schneider said, “but there is little harm to getting the flu shot in my opinion as a physician.”

The CDC expects 171 million to 179 million doses of flu vaccine to be available this flu season.

Schneider said people have misconceptions about the potential side effects of a flu shot.

“You cannot get the flu from the flu shot,” the doctor said, because the vaccine uses only killed viruses, which provoke a response by the immune system but cannot replicate and spread.

Common side effects include some soreness at the injection site, a low-grade fever and muscle aches, but they last only a couple of days and can be treated with over-the-counter acetaminophen (Tylenol), Schneider said. “The side effects are nowhere near as bad as the actual infection itself.”

The flu can make you feel miserable for days with a high fever and muscle aches, but the danger comes from complications such as dehydration and secondary infections. Schneider said 18,000 people were hospitalized last year with flu complications, and Grady saw 95 percent or more of its beds filled at the peak of the flu season between late fall and early spring.

The people hardest hit by complications are younger than 5 years old or older than 65, as well as those who are pregnant or already ill. Anyone in a high-risk group should err on the side of caution and seek medical attention right away for flu-type symptoms, Schneider said, because doctors have tests to diagnose the flu and have effective antiviral medications that can cut the severity and duration of the illness and reduce the chance for complications.

Even if you’re at low risk, getting the shot helps protect high-risk people around you, Schneider said. “If I get the flu shot, I’m much less likely to pass it on if I were to become infected.”

The vaccine is unlikely to be as ineffective as it was last flu season, but it won’t be 100 percent successful. You can help fight the flu by covering yourself when you cough and sneeze, washing your hands regularly, and keeping hand sanitizer around. And if you still get the flu, Schneider said, stay home from work or school.