Late last year, thousands of children across the United States were hospitalized with respiratory syncytial virus (RSV), but unlike previous RSV surges, this one affected a larger number of people and a broader range of age groups, including older children. As cases climbed faster and earlier in the season than in previous years, researchers wondered whether a fast-spreading RSV variant might be driving this unusual pattern of cases.
To learn what was causing the upsurge, a team of scientists and clinical collaborators from Massachusetts General Hospital (MGH) and its outpatient practices in the greater Boston area began collecting specimens from patients diagnosed with RSV and sharing them with scientists at the Broad Institute of MIT and Harvard, who sequenced the viral genomes. They wanted to see if characteristics of the virus, such as the emergence of a new variant, contributed to the severity of the surge.
