Run its course = perish of itself?

Context:

Swine flu pandemic over, says world health body The majority of cases in the UK have shown only mild symptoms The swine flu pandemic has been declared officially over by the World Health Organization.

The body said it was moving to the "post-pandemic phase" after many countries, including the UK, had scaled down their emergency measures.

WHO director general Dr Margaret Chan said the virus had "largely run its course".

Millions of people were affected across the world by the infection after it emerged in April last year.

But the pandemic - the first for 40 years - proved much less deadly than many had feared.