NASHVILLE, Tenn. -- Influenza continues to bite hundreds of people in middle Tennessee, and some doctors said the situation may not improve any time soon.

Video: Doctors Say Flu Season May Stick Around For While

Physicians said some vaccines aren't working this season and some people are unknowingly spreading the bug.

Dr. Pete Powell with Vanderbilt Medical Group said this year cases of the flu are high and continue to rise.

"Our waiting room has been full of people with the flu. It’s increased in the last two or three weeks, which goes along with the national trend," said Powell.

Many people are finding even with the flu vaccine that they're still catching the virus. Doctors said the vaccine given this year isn’t protecting against all strains of influenza.

"It’s not perfect. We've seen people who get the flu shot who are getting the flu, but they seem to be tolerating the flu better than those who have not had the flu shot," said Powell.

Doctors said it’s important to remember that even if you feel that you no longer have the flu, you could still have the flu and be contagious. In fact, doctors said many people are going back to work and school too early after being sick.

Physicians advise that even if a person doesn't feel sick, they could be spreading the virus. Oftentimes the flu can be contagious a day or two before a person starts to feel sick.

Doctors said they expect the number of flu cases to remain high for another three to five weeks.