NHS Greater Glasgow and Clyde has apologised for its handling of the flu vaccination programme this year.
Concerns have been raised about delays, with some of the elderly receiving their letter after the appointment date.
The health board said it was aware of the anxiety felt by those in the over 65 group, who haven’t had the jab yet.
Senior health officials met with MPs and MSPs on Tuesday to hear more detail regarding constituents’ concerns and explain the actions being taken to resolve the situation.
Jane Grant, chief executive of NHS Greater Glasgow and Clyde, said: “On behalf of the health board, I would like to sincerely apologise to all those people who have experienced issues with their flu vaccination appointments.
“We are very sorry for any distress and anxiety this has caused, especially among the more vulnerable members of our local communities.
“There have been a number of challenges with the delivery of the flu vaccination programme and we have taken action to ensure this situation never happens again.”
Ms Grant said the health board wanted to “offer reassurance” to those over 65 still waiting that remaining letters will be sent this week and appointments scheduled to take place before the end of November.
She added: “For those who received their letter after their appointment date, we will ensure that you get an alternative appointment.
“We understand that many people have struggled to get through to our appointment line and we are very sorry for that.
“We have now employed an additional 20 call handlers to manage enquiries so that more people can be supported in a more timely way.
“The flu vaccination programme has been especially challenging this year, due to the increased number of eligible people and because it is vitally important that we adhere to physical distancing guidelines when administering vaccinations.
“However, we will make sure that we learn the lessons from what has happened this year and put measures in place to avoid these issues being repeated.”
If members of the public need to change their appointment, they should contact 0800 707 6699 or email firstname.lastname@example.org