The first genetic analysis of the H1N1 flu has revealed that things may not be as bad as first feared, although scientists admit that history may provide an example that no-one wants to see followed.

British scientists Nicholas Grassly of Imperial College London and Andrew Rambaut of the University of Edinburgh have studied the virus' rate of spread, and discovered that it's much slower than many had thought... in fact, only just fast enough to keep itself from dying out:

If the new virus spreads from one infected person to the next at about the same speed as ordinary flu, that gives an idea of how many cases there may have been in that time. A mathematical model permits the calculation of an important variable called R0 â€“ the number of additional people infected, on average, by each case. If R0 is less than one, an infection dies out.

Grassly also cautions that the estimate is very preliminary. But with the data available now, he gets an R0 of 1.16 â€“ enough for the virus to keep going, but only just.

Don't celebrate just yet, however; New Scientist points out that the flu pandemic of 1918 first presented with a similarly low rate of spread (1.45) that jumped to 3.75 during a more deadly second wave. For now, though, here's hoping that the rate falls just that little bit further to take it over the edge.

First genetic analysis of swine flu reveals potency [New Scientist]