As schoolwork overwhelms students, their immune systems weaken, making them more prone to getting the flu.

University Health Services (UHS) is having its annual flu vaccination clinic today from 11 a.m. to 7 p.m. in HUB Alumni Hall, where students can walk in to receive the $20 shot.

Kathy Petroff, UHS urgent care nurse manager, said more students get flu vaccines each year and more than 2,000 got the flu shot last year.

Students living in residence halls or under crowded conditions are at increased risk of contracting the flu, said Jill Totenberg, a spokeswoman for the Centers for Disease Control and Prevention.

Students often share personal products, which can have germs on them.

Getting the shot now can prevent illness come flu season, which lasts from November through March, peaking in January. Two weeks after receiving the shot, an influenza vaccine can help protect people from the virus for up to a year. While it doesn't guarantee avoiding the flu, officials said it will lessen the virus' effects.

Maxim Health Systems will be providing the vaccines, which are in plentiful supply this year. In years past, UHS has either run out or come close to running out of vaccines, Nagy said.

With the emergence of Severe Acute Respiratory Syndrome, health authorities encourage flu shots even more than in past years.

The disease, which affected much of Asia and parts of North America last year, has similar symptoms to the flu -- including fever, headaches and general aching. Getting a flu shot can prevent wrong diagnoses and help get proper care sooner.

The meningitis shot is $85 and the vaccinations can be charged to students' accounts.

If students can not attend the clinic, appointments can be made anytime on or after tomorrow by calling (814) 863-0774.