Scientific testing is great—except when it has the potential to unleash a global pandemic. That's the word from a new study that warns experiments on mutant viruses could do more harm than good. Scientists around the world are creating new viruses or changing existing ones to better understand how strains evolve and spread, but that's a big problem, say Harvard and Yale researchers. If 10 labs in the US performed high-containment experiments for 10 years, they estimate about a 20% chance that at least one person would become infected and a 1% chance that it would escape the lab, USA Today reports.
"We are not saying this is going to happen, but when the potential is a pandemic, even a small chance is something you have to weigh very heavily," says a Harvard epidemiologist as quoted in the Guardian. Scientists who study bird flu immediately criticized the study, saying their research provides insights that would be otherwise impossible. Two of those quoted created an airborne strain of avian flu in 2012 that was transmissible to mammals, a controversial feat whose details were published only after much debate. (Read more virus stories.)