Apparently the vaccine comes batched in tens and the health professionals are reluctant to open a batch unless they can use all ten shots
Meanwhile arm is still sore (no more so than with any other vaccination) but otherwise no problems to report.
On balance I would not have had it but for the "underlying health issues" which made me think that a few days of a sore arm and other minor side effects might be better than a serious illness or even death should I catch the swine flu, which given my kids bring just about every known ailment home each winter, was almost certain to happen.