Some stories rise up the news agenda then fall, all in a single day.
Some linger longer.
Others hover persistently in the background, occasionally breaking through.
Swine flu falls into the latter category.
When first detected, it was dominant.
Remember the fuss when the first confirmed cases arrived back in Scotland?
The grim expectation must be that it is about to become dominant as a news issue again.
We must all simply hope that the vaccination programme is as successful as possible in limiting the impact.
On this issue, as Health Secretary in Scotland, Nicola Sturgeon has proved capable, steady and focused.
She has offered the right balance of blunt warnings tempered by sensible reassurance.
She has worked co-operatively with counterparts in London.
Due praise too for health officials in Scotland who have responded efficiently to date.
Again, we must simply hope that this effort is sustained in the notably challenging period ahead.