An email was sent to contractors on Thursday urgently seeking staff for the following day.
"Due to extreme staffing shortages for tomorrow (Friday) the Staff Bank will be able to accommodate ANY hours that you are able to work,” the email read.
The staff bank urged contractors to contact them if they could only work partial shifts, as due to the shortage of staff this could be accommodated.
"We’d like to thank all of our vaccinators who have helped make sure the roll out is a success across Greater Glasgow and Clyde,” a spokesperson said.
"We schedule our vaccinator shifts in line with supply of vaccine and number of appointments and utilise NHSGGC staff, including bank staff and contractors, where required.
"We required additional staff at two of our vaccination sites and were able to fill those shifts. All sites remain open and continue to operate as normal.”
This is not the first time health boards have faced staff shortages in vaccine centres.
At the end of May, NHS Lothian warned of “critical” shortages in a similar plea to contracted staff, before members of the Armed Forces were brought in to help.
Some pharmacists have said the staff shortages are a result of a dispute over pay, with the Scottish Government initially paying contracted pharmacists £66 per hour, but subsequently downgrading this to £15 an hour.
Some other contracted staff, including dentists and optometrists, remain on the higher rate.
The Scottish Government has said this rate was never meant to apply to individual pharmacists, but was rather intended to compensate a practise or pharmacy for the loss of a staff member during their vaccination work.
The discrepancy in pay also angered nurses, who were receiving the £15 rate.
One pharmacist, who previously worked on the vaccination programme, called the situation “a mess” and said “incompetence” was causing the staff shortages.
"The people of Scotland deserve better,” he said.