SWINE flu vaccinations for front-line staff at Barnsley Hospital started on Monday.
The vaccination programme will be rolled out over the next few weeks with GP surgeries receiving deliveries of the drug from next week.
Health care staff will be immunised first as they are at increased risk of catching and transmitting the infection.
Patients will be prioritised with those in the 'at risk' category age six months to 65 getting immunised first.
Pregnant women, cancer patients and anyone with a compromised immune system will be next followed by those over 65 in the clinical 'at risk' group.
Healthy pensioners will not automatically be considered as they appear to have some immunity to the disease.
Patients will be contacted by their GPs if they fall into any of the priority groups.
