H1N1 pandemic virus analyzed

by bruno

Nature’s editor says (bolds are mine):

A phylogenetic analysis of swine-origin H1N1 influenza A virus provides evidence that the virus is a reassortment possessing genes from avian, swine and human origin viruses. The pandemic virus appears to have evolved in way typical of swine flu sequences prior to entering humans, and is derived from several viruses circulating in swine. Initial transmission to humans appears to have occurred several months before recognition of the outbreak. An estimate of the gaps in genetic surveillance points to a period of years between the reassortment of swine lineages and the transfer to humans and the multiple genetic ancestry is inconsistent with an artificial origin for the virus. The gaps in out knowledge revealed by this work highlight the need for the systematic surveillance of influence in swine as a means of identifying potentially pandemic strains before they cross into human populations.

The paper can be found here.