The state Health Department is warning those who are unvaccinated to get the flu shot immediately to combat what they are calling a "significant threat to public health" as flu cases begin to rise.

Dr. Lavonne Valembrun, NYC Health + Hospitals/Kings County says flu symptoms are hard to ignore.

“You will know if you have the flu, if you have the sudden onset of body aches and pains,” says Dr. Valembrun. “We don't know why more people are having the flu earlier and earlier like last year, but in my opinion it's because less people are taking the flu shot.”

The Health Department says those with the flu should stay home, wash their hands with soap and hot water and use hand sanitizer.