Genetic Diversity and Evolutionary Dynamics of Respiratory Syncytial Viruses (RSV)

Human respiratory syncytial virus (RSV) causes acute lower respiratory tract infection (ALRI) in young children and certain adults groups, including the immunocompromised and elderly. Nearly all children are infected with RSV by 2 years of age. It has been estimated that for 2005 RSV caused 33.8 million new episodes of ALRI in young children worldwide, requiring hospitalization due to severe illness in 3.4 million cases. Rapid antigenic and genetic diversity has been found in RSV circulating in humans. Despite its global public health impact, a completely protective RSV vaccine has yet to be developed. Human RSV can be classified into two antigenic groups (A and B), each containing several distinct subgroups based on antigenic and genomic sequence differences, especially in the G glycoprotein. It is unclear if this represents a gradual evolution of the viral genome, or stochastic difference in infection rates by co-circulating strains. The severity of illness ranges from mild cold symptoms to life threatening. Our collaborative RSV sequencing projects will be used to: 1) compare RSV sequences from outpatients with mild disease with those from inpatients with severe disease to identify key genomic signatures of virulence and 2) determine the mechanisms through which infant RSV infections result in asthma by focusing on both host and viral determinants of illness.

Funding