Pharmacies across the province are having trouble keeping up with demand for flu shots but health officials say the problem is not with the overall supply of the vaccine.

A recent spike in the number of Albertans diagnosed with the flu prompted many to seek out the flu shot at clinics and pharmacies. However, the demand has turned out to be more than most pharmacies are used to.

"We ran out of vaccine New Year's Eve and so we ordered some earlier that day, and got the order Friday," said Heather Walker, a Calgary pharmacist. "But [we] only got half of what we ordered."

Alberta Health Services says it is working overtime to distribute enough vaccine to pharmacies, but Walker says she can't guarantee when she'll have enough for her customers.

Meanwhile, the mass immunization clinics are well-supplied — but facing massive lineups.

At Brentwood Village Mall, 2,000 people lined up for the flu shot on Saturday. Those people faced waits of up to three hours.

For complete details on clinic locations and hours, call Health Link Alberta toll free at 1-866-408-5465 or visit albertahealthservices.ca/influenza.