Vaccinations and healthcare staff - why the reluctance?

So, Dr Ian Salisbury of the  DH is complaining about the low uptake of flu vaccinations amongst NHS staff. Amongst the whole healthcare economy - a third is in the independent sector (p.s. usually not for profit organisations such as Charities) - the pro vaccination message has been under sold (it saves money) and even more tricky is getting to have the vaccination.
Unless the G.P. is sympathetic it is difficult to persuade receptionists you should be allowed to book to have the jab; our family experience makes it clear that the numbers of chronic conditions that should indicate you're a higher priority are being whittled down, again making access more difficult.
Yes the injection is potentially painful - and if you're at a desk job not so bad - but the physical work of nursing and many other healthcare jobs makes the discomfort more noticeable.
It does have a history of making people feel less well for a day or two as well. It may not be full blown flu but leaves those who have physically hard jobs even less able to perform over those days.
If taking up the vaccine is made easier by offering it on site at work, at a time convenient to staff - say 75% of the nursing staff took it up, the situation would improve. However I'm sure health economists would work out the cost to the NHS of an extra couple of days sickness for them all. Would it be a dis-benefit compared to having lower take up rates but more staff available to work?
If as Dr Salisbury says it is a life saver - should the urgent requirement be that all healthcare workers across all sectors not just the NHS be able to have the vaccination free of charge early in the cycle of vaccine availability? That would set a good example, illustrating the value staff members are to the employers; as well as to the nation as a whole of the beneefits of having the vaccination. Public health has never been so important to sustain - it's economic value should be made clear as well as the social and educative benefits too.