Researchers in a Wisconsin lab have created a mutant, highly infectious version of the "Spanish Flu" that killed around 50 million people in 1918—and if you think that sounds completely insane, there are a lot of scientists who agree with you. The University of Wisconsin researchers argue that their experiments will aid the understanding of the pandemic risk posed by bird flu, but other scientists say it is just too risky. "The work they are doing is absolutely crazy. The whole thing is exceedingly dangerous," a former chief science adviser to the British government tells the Guardian. "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."
Lead researcher Yoshihiro Kawaoka—who resumed his work in 2012 after a moratorium on genetically engineering flu viruses ended—tweaked bird flu viruses to create a virus very similar to the one that caused the 1918 pandemic, reports NBC. It was then used to infect ferrets, which are the animals most like humans for catching flu. Since bird viruses need only "a few changes to adapt to humans and cause a pandemic, it is important to understand the mechanisms involved in adaptation and identify the key mutations so we can be better prepared," Kawaoka says. But that explanation isn't good enough for those scientists uneasy about the creation of such a deadly virus—and infected ferrets capable of spreading it—even in the safest labs. "I am worried that this signals a growing trend to make transmissible novel viruses willy-nilly, without strong public health rationale," says a Harvard professor of epidemiology, warning that a catastrophic pandemic could result if the virus escaped or was intentionally released. (He was part of a recent study that warned if 10 labs in the US perform similar high-containment studies for 10 years, the chances of at least one person becoming infected are one in five.)