Figure 2. Transient invasion dynamics for the four two-cluster models studied.
The decimal logarithm of the proportion of infectious hosts for the mutant antigenic cluster (plain lines) and for the resident cluster (dashed lines) is represented as a function of 
. Colours correspond to different partial cross-immunity (
) values: from 
(antigenic shift, no cross-immunity) to 
(antigenic drift, full cross-immunity). Parameter values are given in Table 1 (theoretical set). Initial conditions are: 
, 
.