The virus population size has an

As observed with abundance-based indices, functional indices lack additive properties (replication principle). In this respect the generalization of Hill numbers has been broadened to include measures of functional and phylogenetic CHMFL-ABL-053 (Chao et al., 2010 and Chao et al., 2014a). Due to their novelty it is not yet clear to us how well these indices might be implemented in a VQS scenario, and which of them might be more appropriate.
All functional indices based on genetic distances carry the assumption that genomes which are distant in sequence space are more likely to vary functionally than sequences close in sequence space; this assumption is not fully justified for viral quasispecies because single mutations in viral genomes can affect important traits such as resistance to components of the immune response, or antiviral agents, cell tropism or host range, among others (Domingo, 2016 and Domingo et al., 2012).
In summary, diversity indices used in ecology can be applied to the characterization of viral quasispecies complexity, and can complement the information provided by the measurements currently in use. The complexity concept is necessarily multidimensional, and no single index can capture all what the term complexity entails.