Isolated in the 1950s from persons with upper respiratory tract symptoms (2, 3) , HRVs have become known as the common cold virus because they are implicated in ≈50% of upper respiratory tract infections (4) . Large community surveys, including the Virus Watch studies of the 1960-1970s (5), have shed light on some aspects of HRV biology and epidemiology. HRVs were also observed in LRTIs soon after their recognition (3) , and data supporting a causative association have accumulated over the past decade (6, 7) . HRVs have also been implicated in exacerbations of asthma and chronic bronchitis and are increasingly reported in LRTIs of infants, elderly persons, and immunocompromised patients (4).