Identifying drivers and constraints for reassortment and strain replacement of highly pathogenic influenza A virus

All influenza pandemics during the last 100-years have resulted from gene exchange between the segmented genomes of at least two different virus strains in a process termed reassortment.

During the last decade, we have seen unprecedented waves of outbreaks of highly pathogenic avian influenza (HPAI) viruses of subtypes H5Nx in birds. These viruses have repeatedly infected humans with severe outcomes and high mortality.

They are highly prone to reassortment with other influenza strains and there is an overt risk that they gain the capacity to spread efficiently in the human population and even cause a new pandemic.We will explore the reassortment compatibility among the HPAI H5Nx viruses and assess how they are affected by exchange of specific gene segments from different lineages.

We will also study putative factors behind the phenomenon of strain replacement where new H5Nx variants repeatedly emerge and take over in bird populations.Such knowledge is important for prediction of reassortment events that might result in dangerous virus strains with zoonotic capacity and pandemic potential.