Some 600 people have died from complications of Middle East Respiratory Syndrome (MERS). Three years since the disease surfaced scientists still cannot find a treatment or prevention. (Infected camels are thought to be the initial source of MERS.) But now international researchers using genetically modified cows have created antibodies that combat the disease, perhaps pointing towards a vaccine. The scientists have used cows to better understand human immunity, in this experiment tweaking the cows’ genomes so that they carry a human chromosome.