(WTVO) — Labor Day weekend is the unofficial end of summer, and doctors said that it is already time to talk about getting the flu shot.

Every flu season is different. It all depends on the strain of flu that will be prevalent during the season. Doctors with OSF Healthcare recommend talking to primary care this month, so that residents are ready to make an appointment by October.

This is even more important for seniors and people with underlying health conditions.

“Every year the flu is different, do the vaccines are designed so that they attack that particular flu strain,” said Dr. Jason Kole, director of emergency department services at OSF Healthcare. “So, it’s key that you get it every year.”

Doctors reminded residents that the flu shot can give them headaches, muscle aches or other minor symptoms. Not having any side effects does not mean that the immunization is not effective, however.