The rhinoviruses cause about 40 percent of all colds in adults, according to Turner. He said that the attachment of the rhinovirus to cells in the nose is the initial step in the production of common cold symptoms. Although there are more than 100 different types of rhinovirus, 90 percent of the types attach to the human cell by the same receptor (called ICAM-1). BIRR4 is a soluble form of the ICAM-1 receptor. Administration of BIRR4 through the nose allows the BIRR4 to occupy the receptor binding sites on the virus and prevent attachment of the virus to nasal cells.

In conjunction with Frederick Hayden, M.D., of the University of Virginia in Charlottesville, Turner performed four studies designed to evaluate the effectiveness of this approach in the prevention of rhinovirus infection and illness. The work was supported by Boehringer Ingelheim Pharmaceuticals, Inc. of Ridgefield, Conn.

Volunteers were treated with either BIRR4 or a placebo either just before or just after infection with the virus. Two different formulations, a solution and a powder, were studied. Regardless of which formulation was used, or when the drug was given in relation to the virus challenge, a beneficial effect was seen. Overall there was a significant reduction in the severity of cough, stuffiness, headache, runny nose, sneezing and sore throat.

“Treatment with BIRR4 also caused a significant reduction in the host immune response that has been associated with symptom severity,” said Turner, “but there was no effect on the ability of the volunteers to produce the immune response that would protect them from future infection with the virus.”

The results suggest that treatment with BIRR4 has a beneficial effect on common cold symptoms. It remains to be determined whether the treatment will have a beneficial effect on the complications of rhinovirus colds, such as middle ear infections, sinusitis and asthma.