Evolutionary dynamics of RSV-A in recurrent epidemics

Together with our collaborators Prof Graham Medley at London School of Hygiene and Tropical Medicine, and Prof Patricia Cane at Public Health England, we have published a paper in the Journal of Virology describing the molecular evolutionary dynamics of RSV-A in Coastal Kenya. This is part of an on-going study aimed at understanding the epidemiology and disease burden of RSV-associated pneumonia cases in this region.

We used G-gene sequence data from samples collected at the Kilifi County Hospital between 2000 and 2012. We observed high genetic diversity in circulating RSV strains within and between epidemics at both local and global settings. While investigating how the RSV strains (i.e. genotypes and sub-genotypes/variants) persist in the community, we found that there is sequential replacement of genotypes after about 7 years and a high turnover of variants within an epidemic and from one epidemic to the next.

The observed genetic diversity is predicted to be associated with variation in antigenic profiles. These observations provide an explanation for recurrent RSV epidemics and have potential implications on the long-term vaccine effectiveness.

Dialogue & Discussion