Due to high demand and low supply of flu vaccine this season, University Health Services (UHS) will be offering the preventative treatment to high-risk patients only.

All off-site vaccination clinics have been cancelled until further notice.

The vaccination clinic scheduled for today in Loker Commons will not be held, but if patients believe themselves to be at high risk, they can receive the inoculation on Tuesday and Thursday afternoons through Dec. 7 from 1 to 5 p.m., on the 3rd floor of UHS.

According to Dr. David S. Rosenthal '59, director of UHS, this year's shortage is due to a donation by UHS to the city of Cambridge. Although UHS received an adequate amount of vaccine from its supplier, the city faced a shortage of 1,000 to 2,000 doses.

"We felt uneasy about having just walk-in care without taking care of high-risk patients first," Rosenthal said.

UHS has already immunized about 5,000 people this season from an initial supply of around 7,000 doses. It donated some of the remaining supply to the city.

Should the city of Cambridge not need all the doses donated, it will return them to UHS later in December. Whether or not that will happen, though, is uncertain.

"We're checking day by day," Rosenthal said.