Results of the researchers' study, published in the Journal of Experimental Medicine, show that by simply delaying when an infant suffers from respiratory syncytial virus (RSV) the major cause of common cold in adults may make the difference.

RSV will infect most children during the first year of life and can keep re-infecting, as it is able to get around the immune system. For some infants RSV leads to bronchiolitis, one of the major causes of infant hospitalisation in the Western world. And around 40 percent of infants who experience bronchiolitis as a result of RSV infection are subsequently affected by recurring wheeze and asthma in childhood.

Professor Peter Openshaw from Imperial College London at St Mary's Hospital says: "Although there is still no way to prevent babies being infected by RSV, keeping people with colds away from young babies could reduce the chances of infection. Merely delaying infection beyond the first six months could have a significant impact on the later health of a child."

In tests carried out in mice, researchers were able to show that delaying RSV infection can have a significant effect on cytokine production and lung pathology during subsequent re-infection.

Dr Fiona Culley from Imperial College London at St Mary's Hospital says: "What is interesting from the point of view of our understanding of immunology, is just how differently the immune system deals with RSV infection at different ages, and the long-term consequences that neonatal infection can have on immune responses and pathology later in life."

Primary RSV infection in newborn mice followed the same viral kinetics as in adults but was associated with reduced and delayed IFN-y responses. For the study,
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Contact: Tony Stephenson
at.stephenson@ic.ac.uk
44-207-594-6712
Imperial College London
18-Nov-2002