Figure 2
From: Antigenic drift and epidemiological severity of seasonal influenza in Canada
Relationship between the epidemiological severity (as measured by the Severity Index) and the genetic drift of influenza (as measured by the mean Hamming distance between a season and the previous one). Each row represents a type/subtype and each column a different definition of the antigenic distance. The label next to each point indicates the starting year of the epidemic season (e.g., 2014 for the 2014/2015 season). The size of the point is proportional to the vaccine effectiveness observed that year for a given type/subtype.
