The head of NHS Scotland has warned it could take almost a year and a half to vaccinate everyone north of the border against swine flu.

Chief executive Kevin Woods has written to health boards advising there may not be enough vaccination to cover the entire population until November 2010.

Dr Woods wrote: “According to current delivering estimates, vaccine for 100% of the population could be received by November 2010.”

He believes the first batches of the vaccine should arrive in the country by August, while a “significant proportion” of vaccine stocks - possibly enough for half the population - could arrive before the end of 2009.

However, Tory health spokeswoman Mary Scanlon said there had been an “understanding” that there would be sufficient vaccine for all the population over the winter months.

She added: “Given we are being told that the H1N1 virus could mutate into something more serious, I think this development is of very real concern.

“I hope the Scottish Government will look at all the options to increase the supply of vaccine over the winter months, before a real crisis hits.”