"Scientists today identify seven virus families that cause the majority of colds: rhinovirus, coronavirus, influenza and parainfluenza virus, adenovirus, respir

"Scientists today identify seven virus families that cause the majority of colds: rhinovirus, coronavirus, influenza and parainfluenza virus, adenovirus, respiratory syncytial virus (RSV) and, finally, metapneumovirus, which was first isolated in 2001."