Don’t just rely on that apple in the dining hall to keep the doctor away this coming winter.

In preparation for the flu season, Harvard University Health Services is offering free flu shots to Harvard students, faculty, and staff with a valid Harvard ID or Harvard University Group Health Plan card.

“We want to keep the community as healthy as possible throughout the winter,” UHS Director David S. Rosenthal ’59 said. “The more people we can vaccinate, the less risk the entire community has of getting the flu.”

Since Aug. 1, UHS has vaccinated 9,700 people, of which 1,500 were undergraduates, Rosenthal said. Like in previous years, UHS has ordered 15,000 doses of flu vaccine.

A highly contagious viral infection, the flu is easily spread from person to person through talking, sneezing, and coughing.

UHS will administer flu vaccination clinics on Mondays and Tuesdays from 12 to 3 p.m. on the second floor of its building on 75 Mt. Auburn St. through the end of December.

Rosenthal said more students are vulnerable to getting the flu in the winter, when the weather keeps them inside and close to other students.

“Given that students live in close communities and spend many hours together in classrooms, the flu can easily spread quickly through entryways, entire buildings, and classes,” Rosenthal said.

The vaccine, however, is not entirely effective. It is like a game of chance in that each year, scientists try to match the viruses in the vaccine to those most likely to cause illness that year.

“The vaccine does not prevent illness from other viruses, but getting the vaccine significantly decreases your risk of being ill from the viruses that are expected to be most common,” Rosenthal said.

Adeline E. Byrne ’14, a skier on the Nordic Crimson, said she gets the flu shot every year because catching the flu “could ruin my season,” she said.

“I might also get other people sick when I have the flu,” she added.

Byrne said she has yet to find the time to get vaccinated this year, but she plans to do so as soon as her schedule opens up.

Unlike Byrne, Lloyd S. Han ’12 said he never gets the flu shot.

“Basically the flu shot is a guess at which strains will be hitting this season, so it’s not guaranteed to help,” Han said. “And I’m also super lazy.”