Current swine flu virus may be more virulent than 2009

A swine flu virus that has killed more than 1,200 in India may be more dangerous than the strain responsible for the 2009 pandemic, scientists have warned.

Experts believe new sub-strains of H1N1 flu might have acquired mutations, changes in the genetic code, that increase their virulence.

The findings from a study published in the journal Cell Host & Microbe contradict reports from Indian health officials that the virus has essentially remained unchanged since it emerged six years ago.