With winter in full swing, federal health officials say so is flu season.

Every state is reporting influenza outbreaks and officials from the Centers for Disease Control and Prevention say that the outbreaks are worse than last year. While it’s difficult to estimate the flu toll until the end of the season, experts are saying that in 2016 to 2017 influenza viruses have been identified more frequently in the United States.

They recommend that people get vaccinated. This year the flu vaccine protects against three or four strains. Some symptoms to look out for if you think you have the flu are fever, chills, coughs, sore throat, fatigue and even headaches.

Flu season has a tendency to peak during the months of January and February.