CALGARY -- Alberta Health Services says it's aware of social media posts claiming false vaccine bookings were made with the intent of clogging up the system -- and the posts have been brought to the attention of law enforcement.

One tweet of concern shows a screenshot of a confirmed appointment at an AHS vaccination centre and the author says they planned to let the unused vaccine spoil rather than allowing it to be administered to others.

AHS says there has not been a significant increase in appointment no-shows, and all 1,300 Alberta pharmacies participating in the vaccine rollout have been notified of the nefarious social media claims.

A system is in place to prevent Albertans from making multiple bookings online or through Healthlink 8-1-1.

As of Monday, AHS says there have been 2,593 "vaccine refusals" -- people who booked an appointment and for reasons which may include fear of needles or not wanting the vaccine they are offered -- have declined the shot.

Nearly 2.3 million doses of vaccine have been administered in Alberta so far.

Just over 50 per cent of Albertans aged 12 and up have received at least one dose of vaccine, and seven per cent are now considered fully immunized after receiving their second dose.