Not with a bang, but a whimper

Jeremy Laurance: Swine flu: the pandemic that ended with a whimper

So that's it. The swine flu pandemic of 2009 is over. The World Health Organisation (WHO) has acknowledged that the pandemic "may have peaked in parts of the northern hemisphere". In the UK, cases have been declining for four weeks and are now only just above baseline levels. Swine flu is not going to return this side of Christmas.

Can we relax? Not yet. Chief medical officer Sir Liam Donaldson says there could be another peak in January or February and, more worrying, the virus could mutate.

But suppose it does not? Will the WHO have to redefine the term "pandemic virus"? The only pandemic we have seen so far is the one at the end of the virologists' microscopes. OK, so it is a completely new flu virus of a kind never seen before – hence its title "Novel H1N1 influenza". But there has been no "pandemic", in any clinically relevant sense of the term, anywhere in the world since swine flu first broke out in Mexico last April.