in the united kingdom, the common cold unit (ccu) was set up by the medical research council in 1946, and it was here that the rhinovirus was discovered in 1956. in the 1970s, the ccu demonstrated that treatment with interferon during the incubation phase of rhinovirus infection provided some protection against the disease. no practical treatment could be developed. the unit was closed in 1989, two years after it completed research of zinc gluconate lozenges in the prevention and treatment of rhinovirus colds. zinc was the only successful treatment developed in the history of the ccu.