The H5N1 strain bird flu deadly virus kills half people catch it.Fortunately , ’ easily spread person person , usually contracted though close contact infected birds.But scientists Netherlands genetically engineered much contagious airborne version virus quickly spread among ferrets use experimental model disease might transmitted among humans.And researchers University Wisconsin-Madison used samples corpses birds frozen Arctic recreate version virus similar one killed estimated 40 million people 1918 flu pandemic.It ’ experiments like make David Relman , Stanford microbiologist co-director Center International Security Cooperation , say 's time create better system oversight risky research man-made super virus escapes lab causes next global pandemic .