Tens of thousands of at-risk people have left themselves vulnerable to flu by failing to get jabs, the latest figures show.
Unseasonably mild weather could be to blame for the poor take-up of free vaccinations, some experts fear.
Take-up remains lower than this time last year.
And health chiefs have urged pregnant women and others likely to suffer worst if they catch the winter bug to get protected.
More than 3,000 healthy north-east mums-to-be are yet to get a jab despite huge efforts to raise awareness of the risks.
That is almost two thirds of expectant women in the NHS Grampian area and makes them the least-protected group.
Some 10,000 over-65s have heeded recent warnings and sought help in the last month – but that still leaves 33,000 who have not.
There are a total of 45,500 younger people in at-risk categories – 60% of those eligible for free jabs – who are still to come forward.
That includes more than 6,500 with chronic respiratory disease.
Poor take up comes despite NHS bosses using letters, texts and calls to alert eligible people and putting on weekend and evening clinics.
In the NHS Highland area, around 25,000 over-65s have not had their vaccination and just over 24,000 younger patients considered at risk.