Scientists recreate deadly Spanish flu
Spanish influenza killed 50 million people in 1918. Now US researchers who have copied the virus have been labelled 'crazy' by opponents
Scientists have created a life-threatening virus that closely resembles the 1918 Spanish flu strain that killed an estimated 50 million people in an experiment labelled as "crazy" by opponents.
US researchers said the experiments were crucial for understanding the public health risk posed by viruses currently circulating in wild birds, but critics condemned the studies as dangerous and called on funders to stop the work.
Scientists at the University of Wisconsin-Madison used a technique called reverse genetics to build the virus from fragments of wild bird flu strains.
They then mutated the virus to make it airborne to spread more easily between animals.
"The work they are doing is absolutely crazy. The whole thing is exceedingly dangerous," said Lord May, the former president of the Royal Society and one-time chief science adviser to the British government. "Yes, there is a danger, but it's not arising from the viruses out there in the animals, it's arising from the labs of grossly ambitious people."
Influenza viruses circulate freely in wild bird populations. Most remain in chickens, ducks and other birds, but occasionally strains mutate into a form that can infect humans. The H5N1 bird flu strain has killed at least 386 people since 2003, according to the World Health Organisation. The Spanish 1918 flu is also thought to have come from birds.