Characterisation of rotavirus strains emerging in the vaccine era

Summary This project will provide a unique insight into the diversity of strains circulating in the vaccine-era and support efforts to maintain an effective immunisation program.

Project Details

Rotaviruses are the most common cause of severe diarrhoea in young children worldwide. To reduce this burden of disease, the rotavirus vaccines, Rotarix and RotaTeq, have been introduced in the National Immunisation Programs of 100 countries. Both vaccines were included in the Australian National Immunisation Programs on 1 July 2007, and vaccine coverage of 84% has been achieved leading to a significant reduction in children ≤5 years of age hospitalised with acute gastroenteritis. The high vaccine coverage in the Australian paediatric population and resulting herd immunity may impact the diversity of rotavirus strains circulating in the community, driving the evolution of vaccine-escape strains, which may reduce the long-term effectiveness of the vaccination program.

The Australian Rotavirus Surveillance Program has monitored rotavirus strains causing hospitalisation across Australia for over 20 years. We have observed several changes in the diversity of rotavirus strains in the decade following vaccine introduction; which is suggestive of a vaccine-derived effect at the population level. The Northern Territory, Western Australia, New South Wales and South Australia have experienced rotavirus outbreaks occurring in vaccinated and unvaccinated children, and the elderly, where rates of rotavirus disease approached those reported in the pre-vaccine era. The aim of this project is to characterise these emerging rotavirus strains and understand their evolution in context of global rotavirus isolates.

This project will combine both laboratory experiments and bioinformatics analysis. The methods utilised in this project will include RT-PCR, generating libraries for Next Generation Sequencing, computational pipelines for genome assemblies, phylogenetic analysis, and Bayesian analysis, to describe the evolution of these emerging strains. This project will provide a unique insight into the diversity of strains circulating in the vaccine-era and support efforts to maintain an effective immunisation program.